用括号内所给单词的适当形式填空.
1. Mrs Zhang (be) a driver twenty years ago.
2. Liu Hai is our teacher. He (teach) English.
3. —Was your grandpa a teacher?
—Yes, he was. He ___ (teach) Chinese.
4. I (read) a book at home yesterday.
5. Chen Hai (study) art very hard five years ago.
6. Her mother (walk) to work the day before yesterday.