(      )7． If you were in Sahara，you ________ the value of fresh water．

40．I _________ (watch) TV when someone knocked at the door．

39． —What   (happen) to Herry last night?   ．

—He_________ (fall) down and_________ (hurt) his leg．

38． By the time l_________ (get) up，my mother _________ (get) the breakfast ready．

37． English__________ (speak) by many people．

36． When Terry_________ (come) to school he_________ (realize) that he_________ (leave) his homework at home．

33．Jimmy said，"l have read the book．”（合并为一个复合句）

Jimmy_________ _________ _________ _________read the book．

35．1 don-t know what should I do with these books．（改为简单句）

I don-t know what_________ _________with these books．

34． The girl with a flower in her hand is my sister．（改为含有定语从句的复合句）

The girl_________ _________ a flower in her hand is my sister．

31． He had writtentenletters to his pen pal．（对划线部分提问）

_________ _________Letters _________he written to his pen pal?