Ответ:

3.1. wrote 2. understood 3. became 4. could 5. thought 6. sold

4. 1. I didn't do my English homework but I did my Maths homework.

2. I ate the meat but I didn't eat the vegetables.

3. Ella went to Mike's party but she didn't go to Henry's party.

4. We had Biology today but  we didn't have History.

5. My parents didn't learn French at school  but they learned English.

5. 1. When did you get home from London?

2. Where did you stay in London?

3. Whom did you meet in Trafalgar Square?

4. What did you have for dinner?

5. How did you travel to London and back?

Объяснение:

Для образов. предложений в Past Simple глагол смотрим во втором столбце таблицы неправильных глаголов( buy  - bought).  Если глагола там нет, значит  он правильный, тогда + окончание - Ed к нему ( play - played).

Отрицательное предложение:  После подлежащего + didn't + глагол. -  He didn't play ball yesterday.   My sister didn't have breakfast in the morning.