1.Mary____(be) a cheerful child,but she_____(be) very sad yesterday.
2. I ______ (not know) how to read and write befort I ____(go) to school.
3. My father______(become) a teacher when he_____(be)only seventeen years old.Now he still_______(work) as a teacher.
4.He___(write) two books last year.Now he____(write) an article for a magazine.
5.She___(be) much better now than she____(be) a week ago.
6.He___(like) his coffee with a lot of milk, but now he____(drink) black coffee only.
7.After Anne Sullivan____(come) to live with the Kellers,Helen's life____(change) completely.
8.When I_____(be) in Shanghai,he often____(come) to see me.
9.It_____(be) a pity that you ____(not go) to the party last night.
10.I____(not have) any money at that time because both my wife and I____(be) out of work.
第二题,before