1,It must be a mistake, musn't it?
2,she must be work in her office now.
3,Someone is knocking at the door,who may it be?
4,There may be some students in the classroom,aren't they?
5,He out of breath when he got to school.
6,He received many letters,but he had no time to reply them.
7,She told a very fun story.
8,Would you mind give us some advice on how to learn maths?
9,Engels wrote a letter to Marx,praised him for it.
10,This is a book named Introduction of Japanese.
11,She is considering change a job.
12,Wine is made of grain.
13,The doctor has spent much time in research into heart disease.
14,The professor gave us some advices on how to learn English well.
15,The doctor advised me take more exercise.
16,What does the weather like today?
17,He is one of the first singer who began to sing pop songs.
19.He pointed at the book,said it was his.
20.He feels like eat somthing,he is too hungry.
21,His father,that is over sixty,still works hard day and night.
22,She has two daughters,neither of them is a teacher.
23,The project,which was lasted four years,cost $1billion.
24,Inside the temple is a row of stone animals,which faces the rising sun.
25,The Nile,from it electricity is produced.no longer flood the areas around.
26,I'd like going to see my friend now.
27,Much of the history are completely unknown.
28,The number of stones was put together to record history.
29,The box is heavy to be carried.
30,He studies English in using this book.
第2 11个为什么？
追答第二题错误很明显啊，意思是 他现在一定在办公室工作，be doing 表示正在做
11 是考查非谓语动词，consider doing sth, 考虑做某事