The Fifth Edition of the CompTIA A+ Complete Study Guide: Core 1 Exam 220-1101 and Core 2 Exam 220-1102 offers accessible and essential test preparation material for the popular A+ certification. Providing full coverage of all A+ exam objectives and competencies covered on the latest Core 1 and Core 2 exams, the book ensures you'll have the skills and knowledge to confidently succeed on the test and in the field as a new or early-career computer technician.
The book presents material on mobile devices, hardware, networking, virtualization and cloud computing, network, hardware, and software troubleshooting, operating systems, security, and operational procedures. Comprehensive discussions of all areas covered by the exams will give you a head start as you begin your career as a computer technician.
This new edition also offers:
* Accessible and easy-to-follow organization perfect to prepare you for one of the most popular certification exams on the market today
* Opportunities to practice skills that are in extraordinary demand in the IT industry
* Access to the Sybex online test bank, with chapter review questions, full-length practice exams, hundreds of electronic flashcards, and a glossary of key terms
Perfect for anyone prepping for the Core 1 and Core 2 A+ exams, CompTIA A+ Complete Study Guide: Core 1 Exam 220-1101 and Core 2 Exam 220-1102 is a must-have resource for new and early-career computer technicians seeking to improve their skills and increase their efficacy in the field.
Inhaltsverzeichnis
Introduction xxvii
Assessment Test lxxxii
Part I 220- 1101 1
Chapter 1 Motherboards, Processors, and Memory 3
Understanding Motherboards 7
Motherboard Form Factors 7
System Board Components 10
Understanding Processors 42
CPU Architecture 43
CPU Characteristics 45
Understanding Memory 49
Important Memory Terms 50
Types of Memory 54
Memory Packaging 59
Understanding Cooling Systems 63
Fans 63
Memory Cooling 66
Hard Drive Cooling 67
Chipset Cooling 67
CPU Cooling 67
Summary 71
Exam Essentials 71
Review Questions 73
Performance-Based Question 1 77
Performance-Based Question 2 78
Chapter 2 Expansion Cards, Storage Devices, and Power Supplies 79
Installing and Configuring Expansion Cards 81
Video 82
Multimedia 83
Network Interface Card 85
Input/Output 87
Adapter Configuration 88
Understanding Storage Devices 89
Hard Disk Drive Systems 90
Solid- State Drives 96
Raid 104
Removable Storage and Media 107
Installing, Removing, and Configuring Storage Devices 114
Understanding Power Supplies 118
Power Supply Input 119
Power Supply Output and Ratings 120
Power Connectors 121
Modular Power Supplies 125
Redundant Power Supplies 126
Replacing Power Supplies 129
AC Adapters as Power Supplies 130
Summary 131
Exam Essentials 131
Review Questions 133
Performance-Based Question 137
Chapter 3 Peripherals, Cables, and Connectors 139
Understanding Cables and Connectors 140
Video Devices 141
Audio Devices 154
Input and Output Devices 156
Storage Devices 159
Understanding Cables and Connectors 160
Peripheral Cables and Connectors 160
Serial Ports 169
Video Cables and Connectors 170
Hard Drive Cables and Connectors 178
Summary 184
Exam Essentials 185
Review Questions 186
Performance-Based Question 190
Chapter 4 Printers and Multifunction Devices 191
Understanding Print Technologies and Imaging Processes 193
Impact Printers 194
Inkjet Printers 196
Laser Printers 205
Thermal Printers 217
3D Printers 218
Installing and Maintaining Printers 223
Printer Interface Components 224
Installing and Sharing Local Printers 229
Installing and Sharing Networked Printers 241
Performing Printer Maintenance 251
Installing Printer Upgrades 257
Summary 262
Exam Essentials 262
Review Questions 264
Performance-Based Question 268
Chapter 5 Networking Fundamentals 269
Understanding Networking Principles 271
Network Types 272
Primary Network Components 279
Network Operating Systems 283
Network Resource Access 283
Network Topologies 286
Rules of Communication 290
Identifying Common Network Hardware 295
Network Interface Cards 295
Cables and Connectors 299
Networking Components 314
Summary 324
Exam Essentials 324
Review Questions 327
Performance-Based Question 331
Chapter 6 Introduction to TCP/IP 333
Understanding TCP/IP 335
TCP/IP Structure 336
Understanding IP Addressing 346
Understanding DHCP and DNS 356
IPv6 365
Understanding Virtual Networks 368
Virtual Local Area Networks 368
Virtual Private Networks 370
Summary 372
Exam Essentials 372
Review Questions 374
Performance-Based Question 378
Chapter 7 Wireless and SOHO Networks 379
Understanding Wireless Networking Technologies 381
802. 11 Networking Standards 382
Bluetooth Networking 393
Long- Range Fixed Wireless 396
Radio Frequency Networking Standards 398
Installing and Configuring SOHO Networks 402
Keys to Planning a Network 402
Choosing an Internet Connection 404
Choosing Internal Network Connections 418
Installing the Network Infrastructure 422
Configuring Wireless Routers and Access Points 433
Summary 449
Exam Essentials 449
Review Questions 451
Performance-Based Question 455
Chapter 8 Network Services, Virtualization, and Cloud Computing 457
Understanding Network Services 459
Server Roles 460
Internet Appliances 473
Legacy/Embedded Systems 480
Internet of Things Devices 482
Understanding Virtualization and Cloud Computing 487
Concepts of Cloud Computing 488
Concepts of Virtualization 499
Summary 515
Exam Essentials 516
Review Questions 518
Performance-Based Question 522
Chapter 9 Laptop and Mobile Device Hardware 523
Working with Laptop and Mobile Device Hardware 526
Understanding the Differences between Device Types 526
Disassembling and Reassembling Laptops 531
Installing and Configuring Laptop Hardware 535
Setting Up and Configuring Accessories and Ports 580
Summary 584
Exam Essentials 585
Review Questions 586
Performance-Based Question 590
Chapter 10 Mobile Connectivity and Application Support 591
Understanding Mobile Connectivity 593
Understanding Cellular Networking Standards 595
Using Cellular Data Connections 597
Establishing Wi- Fi Connectivity 608
Establishing Bluetooth Connectivity 622
Understanding Mobile App Support 635
Understanding Location Services 635
Understanding Mobile Device and App Management 641
Configuring Mobile Device Synchronization 654
Syncing Android Devices 666
Summary 668
Exam Essentials 668
Review Questions 670
Performance-Based Question 674
Chapter 11 Troubleshooting Methodology and Resolving Core Hardware Problems 675
Using the Troubleshooting Best Practice Methodology 678
Step 1: Identify the Problem 678
Step 2: Establish a Theory 683
Step 3: Test the Theory 684
Step 4: Establish a Plan of Action 687
Step 5: Verify Functionality 688
Step 6: Document Findings 689
Troubleshooting Motherboards, CPUs, RAM, and Power Problems 690
Identifying General Hardware Symptoms and Causes 691
Identifying BIOS/UEFI and POST Routine Problems 696
Identifying Motherboard and CPU Problems 700
Identifying Memory Issues 702
Identifying Power Supply Problems 705
Summary 708
Exam Essentials 709
Review Questions 711
Performance-Based Question 715
Chapter 12 Hardware and Network Troubleshooting 717
Troubleshooting Storage Drives and RAID Arrays 721
Lights and Sounds 722
Devices Not Found 723
Performance Issues 724
S. M. A. R. T. Diagnostics 725
RAID Issues 729
Optical Drive Issues 730
Troubleshooting Video, Projector, and Display Issues 731
Video Input Issues 731
Video Image Problems 732
Other Display Issues 735
Troubleshooting Common Mobile Device Issues 737
Power and Heat Issues 738
Input Problems 741
Connectivity Issues 743
Physical Damage and Malware 748
Troubleshooting Printer Problems 751
Impact Printer Problems 752
Inkjet Printer Problems 755
Laser Printer Problems 759
Managing Print Jobs 772
Troubleshooting Networking Problems 779
Using Network Troubleshooting Tools 779
Resolving Connectivity Issues 799
Summary 806
Exam Essentials 806
Review Questions 809
Performance-Based Question 813
Part II 220- 1102 815
Chapter 13 Operating System Basics 817
Understanding Operating Systems 819
Operating System Terms and Concepts 821
Operating Systems 823
Minimum System Requirements 828
Understanding Applications 830
System Requirements for Applications 830
Application Installation 832
Security Considerations 835
Other Considerations for New Applications 835
Introduction to Windows 10 836
Windows Editions 836
Windows Features 840
The Windows Interface 851
What's in a Window? 864
File Management 867
Preparing for the Exam 871
Summary 872
Exam Essentials 872
Review Questions 874
Performance- Based Question 878
Chapter 14 Windows Configuration 879
Interacting with Operating Systems 882
Task Manager 882
Microsoft Management Console 888
Additional Tools 899
Control Panel 905
Windows Settings 937
The Windows Registry 960
Disk Management 962
Getting Disks Ready to Store Files and Programs 963
Checking the Health of Hard Disks and Optimizing Their Performance 969
Summary 970
Exam Essentials 970
Review Questions 972
Performance- Based Question 976
Chapter 15 Windows Administration 977
Installing and Upgrading Windows 980
Windows Installation Options 982
The Installation Process 984
The Upgrade Process 1002
Repair Installation 1006
Recovery Partition 1007
Side- by- Side Upgrading Windows 10/11 1007
Image Deployment 1008
Upgrading Editions of Windows 1008
Security and Feature Updates 1008
Installation/Upgrade Boot Options 1011
Considerations 1012
Command- Line Tools 1013
Networking in Windows 1030
Networking Models 1030
User Authentication 1034
Establishing a Network Connection 1036
Accessing Resources 1041
Firewall Settings 1044
Client Network Configuration 1046
Summary 1050
Exam Essentials 1050
Review Questions 1052
Performance- Based Question 1056
Chapter 16 Working with macOS and Linux 1057
macOS and Linux 1060
Applications on macOS 1061
Installing Applications from the App Store 1061
Installing Downloadable Applications 1062
Managing Applications 1064
Creating Shortcuts 1065
Best Practices 1065
Scheduled Backups 1065
Scheduled Disk Maintenance 1068
System Updates/App Store 1068
Patch Management 1069
Driver/Firmware Updates 1070
Antivirus/Antimalware Updates 1071
Tools 1071
System Preferences 1073
Features 1082
Basic Linux Commands 1087
Understanding the Syntax of Shell Commands 1088
Discovering and Using Linux Commands 1089
Becoming root (Super User) 1091
Maintaining the Operating System 1092
Managing Processes 1095
Directory Navigation 1097
Directory Listings 1098
Changing Permissions and Ownership 1099
Working with Files 1100
Working with Directories 1103
Networking Utilities 1104
Getting Help 1106
Linux and Windows 1106
Summary 1108
Exam Essentials 1109
Review Questions 1110
Performance- Based Question 1114
Chapter 17 Security Concepts 1115
Physical Security Concepts 1121
Access Control Vestibule 1121
Badge Reader 1122
Video Surveillance 1122
Motion Sensors 1123
Alarm System 1124
Door Locks 1124
Equipment Locks 1125
Security Guards 1127
Fences 1127
Bollards 1128
Physical Security for Staff 1128
Key Fobs 1129
Smartcards and RFID Badges 1129
Keys 1130
Biometrics 1131
Lighting 1132
Magnetometers 1132
Logical Security 1132
Principle of Least Privilege 1133
Access Control Lists 1133
Authentication Factors 1135
Multifactor Authentication 1135
Mobile Device Management (MDM) 1137
Active Directory 1138
Malware 1143
Ransomware 1144
Trojans 1144
Keyloggers 1145
Rootkits 1145
Spyware 1145
Cryptominers 1146
Viruses 1146
Virus Transmission in a Network 1150
Botnets 1151
Worms 1151
Mitigating Software Threats 1151
Antivirus 1152
Antimalware 1153
Recovery Console 1154
End- User Education 1154
Software Firewalls 1156
Reinstalling the OS 1158
Social Engineering Attacks, Threats, and Vulnerabilities 1159
Phishing 1160
Shoulder Surfing 1161
Tailgating 1161
Impersonation 1162
Dumpster Diving 1162
Evil Twin 1162
Common Security Threats 1163
Denial- of- Service Attacks 1163
Zero- Day Attacks 1165
Spoofing Attacks 1166
On- Path Attack (Previously Known as Man- in- the- Middle Attack) 1167
Password Attacks 1167
Insider Threat 1168
SQL Injection 1169
Cross- Site Scripting (XSS) 1169
Exploits and Vulnerabilities 1170
Noncompliant Systems 1170
Patching and Updates 1170
Operating Systems Life Cycle 1171
Unprotected Systems 1171
Byod 1171
Security Best Practices 1172
Data Encryption 1172
Setting Strong Passwords 1173
Requiring Passwords 1174
Password Expiration 1175
End- User Best Practices 1176
Account Management 1177
Disable AutoRun 1181
Destruction and Disposal Methods 1183
Recycling or Repurposing Best Practices 1183
Physical Destruction 1185
Summary 1187
Exam Essentials 1187
Review Questions 1190
Performance- Based Question 1194
Chapter 18 Securing Operating Systems 1195
Working with Windows OS Security Settings 1199
Users and Groups 1199
User Authentication 1203
NTFS vs. Share Permissions 1208
Shared Files and Folders 1215
System Files and Folders 1218
Windows Security Features 1220
Web Browser Security 1228
Browser Download and Installation 1228
Extensions and Plug- ins 1230
Credentials Managers 1232
Secure Data Transfers 1233
Settings 1234
Securing a SOHO Network (Wireless) 1239
Changing Default Usernames and Passwords 1240
Changing the SSID 1240
Guest Network Isolation 1240
Setting Encryption 1241
Disabling SSID Broadcast 1242
Wireless MAC Filtering 1242
Frequencies 1243
Radio Power Levels 1244
Antenna and Access Point Placement 1245
Assign Static IP Addresses 1245
WPS 1246
Authentication 1246
Securing a SOHO Network (Wired) 1247
Changing Default Credentials 1247
Upgrading Firmware 1248
Filtering 1248
DHCP 1252
Physical Security 1252
Mobile Device Security 1253
Screen Locks 1254
Remote Wipes and Locator Applications 1256
Remote Backup 1258
Failed Login Attempts Restrictions 1258
Viruses and Malware on Mobile Devices 1259
Operating System Updates 1260
Full- Device Encryption 1260
Multifactor Authentication 1260
Authenticator Applications 1261
Firewalls 1261
Policies and Procedures 1261
IoT Considerations 1263
Summary 1263
Exam Essentials 1264
Review Questions 1265
Performance-Based Question 1269
Chapter 19 Troubleshooting Operating Systems and Security 1271
Troubleshooting Common Microsoft Windows OS Problems 1275
Common Symptoms 1275
Common Troubleshooting Steps 1297
Troubleshooting Security Issues 1309
Common Symptoms 1310
Browser- Related Symptoms 1315
Best Practices for Malware Removal 1318
1. Identify and Verify Malware Symptoms 1318
2. Quarantine Infected Systems 1319
3. Disable System Restore in Windows 1320
4. Remediate Infected Systems 1321
5. Schedule Scans and Run Updates 1323
6. Enable System Restore and Create a Restore Point in Windows 1324
7. Educate the End User 1325
Troubleshooting Mobile OS Issues 1325
Application Problems 1325
Performance Issues 1327
OS Fails to Update 1329
Extremely Short Battery Life 1330
Connectivity Issues 1331
Autorotate Issues 1334
Troubleshooting Mobile Security Issues 1335
Security Concerns 1336
Common Symptoms 1338
Summary 1341
Exam Essentials 1342
Review Questions 1343
Performance- Based Question 1346
Chapter 20 Scripting and Remote Access 1347
Scripting 1349
Scripting Basics 1351
Scripting Languages 1355
Scripting Use Cases 1366
Script Considerations 1373
Remote Access 1375
Remote Desktop Protocol 1375
Virtual Private Network (VPN) 1376
Virtual Network Computing 1379
Telnet 1379
Secure Shell 1380
Remote Monitoring and Management 1381
Remote Access Tools 1382
Security Considerations 1387
Summary 1387
Exam Essentials 1388
Review Questions 1389
Performance- Based Question 1392
Chapter 21 Safety and Environmental Concerns 1393
Understanding Safety Procedures 1395
Identifying Potential Safety Hazards 1395
Creating a Safe Workplace 1407
Understanding Environmental Controls 1417
Managing the Physical Environment 1418
Handling and Disposing of Computer Equipment 1424
Understanding Policies, Licensing, and Privacy 1433
Dealing with Prohibited Content/Activity 1434
Incident Response 1435
Managing Software Licenses 1440
Managing Sensitive Information 1443
Summary 1446
Exam Essentials 1446
Review Questions 1448
Performance-Based Question 1452
Chapter 22 Documentation and Professionalism 1453
Documentation and Support 1457
Ticketing Systems 1458
Asset Management 1462
Common Documentation 1466
Knowledge Base/Articles 1475
Change Management Best Practices 1476
Disaster Prevention and Recovery 1482
Data Backups 1483
Battery Backup/UPS 1489
Power Generators 1490
Surge Protection 1491
Account Recovery Options 1492
Demonstrating Professionalism 1494
Professional Appearance 1495
Communicating with Customers 1496
Using Appropriate Behavior 1500
Putting It All in Perspective 1507
Summary 1508
Exam Essentials 1508
Review Questions 1510
Performance- Based Question 1514
Appendix A Answers to the Review Questions 1515
Chapter 1: Motherboards, Processors, and Memory 1516
Chapter 2: Expansion Cards, Storage Devices, and Power Supplies 1518
Chapter 3: Peripherals, Cables, and Connectors 1520
Chapter 4: Printers and Multifunction Devices 1521
Chapter 5: Networking Fundamentals 1523
Chapter 6: Introduction to TCP/IP 1525
Chapter 7: Wireless and SOHO Networks 1527
Chapter 8: Network Services, Virtualization, and Cloud Computing 1529
Chapter 9: Laptop and Mobile Device Hardware 1531
Chapter 10: Mobile Connectivity and Application Support 1533
Chapter 11: Troubleshooting Methodology and Resolving Core Hardware Problems 1535
Chapter 12: Hardware and Network Troubleshooting 1537
Chapter 13: Operating System Basics 1539
Chapter 14: Windows Configuration 1540
Chapter 15: Windows Administration 1543
Chapter 16: Working with macOS and Linux 1545
Chapter 17: Security Concepts 1547
Chapter 18: Securing Operating Systems 1549
Chapter 19: Troubleshooting Operating Systems and Security 1551
Chapter 20: Scripting and Remote Access 1554
Chapter 21: Safety and Environmental Concerns 1556
Chapter 22: Documentation and Professionalism 1558
Appendix B Answers to Performance- Based Questions 1561
Chapter 1: Motherboards, Processors, and Memory 1562
Chapter 2: Expansion Cards, Storage Devices, and Power Supplies 1563
Chapter 3: Peripherals, Cables, and Connectors 1563
Chapter 4: Printers and Multifunction Devices 1564
Chapter 5: Networking Fundamentals 1565
Chapter 6: Introduction to TCP/IP 1566
Chapter 7: Wireless and SOHO Networks 1566
Chapter 8: Network Services, Virtualization, and Cloud Computing 1567
Chapter 9: Laptop and Mobile Device Hardware 1568
Chapter 10: Mobile Connectivity and Application Support 1568
Chapter 11: Troubleshooting Methodology and Resolving Core Hardware Problems 1569
Chapter 12: Hardware and Network Troubleshooting 1569
Chapter 13: Operating System Basics 1570
Chapter 14: Windows Configuration 1570
Chapter 15: Windows Administration 1571
Chapter 16: Working with macOS and Linux 1575
Chapter 17: Security Concepts 1577
Chapter 18: Securing Operating Systems 1577
Chapter 19: Troubleshooting Operating Systems and Security 1578
Chapter 20: Scripting and Remote Access 1578
Chapter 21: Safety and Environmental Concerns 1579
Chapter 22: Documentation and Professionalism 1579
Index 1581
Exercise 2. 1 Removing an Internal Storage Device 115
Exercise 2. 2 Installing an Internal Storage Device 116
Exercise 2. 3 Removing a Power Supply 130
Exercise 3. 1 Changing the Refresh Rate in Windows 10 143
Exercise 3. 2 Changing the Settings for Multiple Monitors 148
Exercise 4. 1 Identifying the Parts of an Inkjet Printer 203
Exercise 4. 2 Installing a USB Printer in Windows 10 239
Exercise 4. 3 Installing a TCP/IP Printer in Windows 10 242
Exercise 4. 4 Determining if Bonjour Is Installed in Windows 244
Exercise 4. 5 Scanning a Document to Google Drive 250
Exercise 4. 6 Using an Inkjet Cleaning Solution 255
Exercise 4. 7 Installing Memory into a Laser Printer 258
Exercise 5. 1 Pricing Network Cables 313
Exercise 7. 1 The Cost of Networking 422
Exercise 7. 2 Installing an Internal NIC in Windows 10 422
Exercise 8. 1 Configuring Windows 10 to Use a Proxy Server 477
Exercise 8. 2 Using Google's Cloud Services 497
Exercise 8. 3 Enabling Hyper- V in Windows 10 503
Exercise 8. 4 Installing VirtualBox and Lubuntu on Windows 10 508
Exercise 9. 1 Removing Speakers from a Laptop 536
Exercise 9. 2 Removing the Display Assembly 544
Exercise 9. 3 Removing the Display Panel 546
Exercise 9. 4 Removing the Motherboard from a Laptop 549
Exercise 9. 5 Replacing Laptop Memory 553
Exercise 9. 6 Removing an M 2 SSD from a Laptop 557
Exercise 9. 7 Removing a Laptop Keyboard 560
Exercise 9. 8 Disabling a Touchpad in Windows 10 563
Exercise 9. 9 Removing an Internal Laptop Battery 568
Exercise 9. 10 Removing the System Fan 572
Exercise 9. 11 Removing the CPU Heat Sink 573
Exercise 9. 12 Removing the Wireless NIC 574
Exercise 9. 13 Removing the CMOS Battery 575
Exercise 9. 14 Flashing the System BIOS 576
Exercise 10. 1 Connecting an iPhone to a Wi- Fi Network 609
Exercise 10. 2 Connecting an Android Phone to a Wi- Fi Network 611
Exercise 10. 3 Disabling Cellular Use for Data Networking on an iPhone 614
Exercise 10. 4 Disabling Cellular Use for Data Networking in Android OS 616
Exercise 10. 5 Setting Up a VPN in Android 619
Exercise 10. 6 Pairing an Android Device with a Windows Laptop 623
Exercise 10. 7 Pairing an iPhone with a Vehicle's Sound System 632
Exercise 10. 8 Configuring Location Services in iOS 638
Exercise 10. 9 Email Account Configuration on an iPhone 645
Exercise 10. 10 Email Account Configuration in Android 648
Exercise 10. 11 Enabling ActiveSync in iOS 658
Exercise 11. 1 Troubleshooting Practice 707
Exercise 12. 1 Using a S M A R T Software Utility in Windows 729
Exercise 12. 2 Stopping and Restarting the Print Spooler in Windows 10 775
Exercise 12. 3 Renewing an IP Address in Windows 10 787
Exercise 12. 4 Renewing an IP Address from the Command Line 789
Exercise 12. 5 Using the net share Command in Windows 795
Exercise 13. 1 Changing a Screen Saver in Windows 854
Exercise 13. 2 Auto- Hiding the Taskbar 856
Exercise 13. 3 Starting a Program from the Run Window 859
Exercise 14. 1 Working with Task Manager 887
Exercise 14. 2 Working with Performance Monitor 896
Exercise 14. 3 Changing the Time Zone 908
Exercise 14. 4 Showing Hidden Files and Folders 913
Exercise 15. 1 Command- Line Directory Management 1015
Exercise 15. 2 Running chkdsk within Windows 1025
Exercise 15. 3 Running chkdsk at the Command Line 1026
Exercise 16. 1 Installing Applications on macOS 1063
Exercise 16. 2 Uninstalling Applications on macOS 1065
Exercise 16. 3 Working with Files 1103
Exercise 17. 1 Testing Your Antimalware 1153
Exercise 17. 2 Testing Social Engineering 1160
Exercise 18. 1 Examining a Security Token 1207
Exercise 18. 2 Examining File Permissions 1214
Exercise 18. 3 Working with File Hashes 1230
Exercise 18. 4 Setting the Passcode Lock on an iPhone 1255
Exercise 18. 5 Setting the Passcode Lock on an Android Phone 1255
Exercise 19. 1 Reviewing Reliability Monitor 1288
Exercise 19. 2 Manually Creating a Restore Point in Windows 1304
Exercise 20. 1 Creating and Running a Windows Batch Script 1356
Exercise 20. 2 Creating Your First PowerShell Script 1360
Exercise 21. 1 Finding Trip Hazards 1413
Exercise 21. 2 Finding MSDSs 1425
Exercise 22. 1 Understanding Punctuality 1501
Exercise 22. 2 Surprise Someone 1505
