: The lesson typically asks, "Why do people think the writer is mad?". The answer lies in the writer's extreme reaction to the noise, such as their claim that they can hear passing planes even when their house is closed up tight.
If you are referring to , Lesson 21 is titled "Which book?" . This much simpler lesson focuses on basic object identification and the use of the word "one" as a pronoun (e.g., "Give me a book, please... Which book? This one?"). " or perhaps exercises related to its grammar? New Concept English 2 | PDF - Scribd New Concept English Practice And Progress Audio 21
New Concept English 2 Complete Audio - Practice and Progress : The lesson typically asks, "Why do people
mad, drill, hole, sink, repair, insurance, strange behavior : The lesson typically asks