Rewrite these sentences in the past simple or present perfect tense.
1. We (study) a very hard lesson yesterday.
2. We (study) almost every lesson in this book so far.
3. We (watch, never) that television program.
4. He (watch) an interesting program on television last night.
5. My wife and I (travel) by air many times in the past.
6. My wife and I (travel) to Mexico by air last summer.
7. I (read) that novel by Hemingway sevaral times before.
8. I (read) that novel again during my last vacation.
9. I (have) a little trouble with nmy car last week.