1.I was reading a book when he came in.
2.The train has arrived just ./ The train has just arrived.
3.He has been a League member for two years./ He joined the League two years ago.
It is two years since he joined the League.
4.Sorry,I didn't see you.
5.He has been to Beijing twice.
6.I caught a cold two days ago./ I have been in a cold for two days./ It is two days since I caught a cold.
7.I don’t know you were here.
8.He said that he had known about it two months before.
9.He finished reading the book last week.
10.The moon turns round the earth.
11.I have been in this school for twenty years.
12.Tom has been away from school for two days.
13.Where were you born?
14.He will go to the park if it doesn't rain tomorrow.
15.I will be eighteen years next year.
16.She has on a red coat./ She is wearing a red coat.
17.They don't have lunch at home.
18.Listen!the birds are singing!
19.Look at the clouds.It is going to rain.
20.When did they arrive?
21.What were you doing this time yesterday?
22.By the end of last term,we had learned 500 English words.
23.While I was sleeping,he came into my room.
24.He likes watching TV.
25.I heard the noise./ I am listening to the noise.
26.They have a lot of books.
27.It’s half past eight.The students are having an English class.
28.He used to get up at half past six last year.
29The shop has been open for two months..
30.He said that he was going to buy a new computer tomorrow.