Exercise 1.
1, A. have never been
2, B. runs
3, B. will win
4, B. went
5, D. came
6, A. are taking
7, B. to play
8, C. am cooking
9, A, will rain
10, C. should go
11, A. to learning
12, B. working
13, D. has waited
14, C. will earn
15, B. will pass
16, A. going
17, C. has worked
18, D - bought
19, B. the most beautiful
20, A - to learn
Exercise 2.
1, going
2, traveled
3, will finish
4, has lived
5, to cooking
6, are having
7, plays
8, will come
9, was cleaning; was eating.
10, read
11, are flying
12 to study
13, have just moved
14, were watching
15, was visiting
Exercise 3.
1 Lan is the tallest in m class.
2 John spends 2 hours doing his homework.
3, This is the first time I have been to HaLong Bay.
4, While I was reading a book. My mom was making cake
Exercise 4: Đề không có phần gạch chân nên mik không làm được