Sure! Here are the completed sentences for the exercise:

**Ex 17: Cho dạng đúng của động từ trong ngoặc.**

1. Mr Hai **had** lunch at 12.
2. My sister **washes** her face every morning.
3. My computer **was** broken yesterday.
4. He **bought** me a big teddy bear on my birthday last week.
5. My friend **gave** me a bar of chocolate when I **was** at school yesterday.
6. My children **did not do** their homework last night.
7. You **lived** here five years ago.
8. They **watched** TV late at night yesterday.
9. Your friend **was** at your house last weekend?
10. They **did not** be excited about the film last night.

**Ex 18: Chọn đáp án đúng (A, B, C hoặc D) để điền vào chỗ trống.**

1. They **didn't catch** the bus yesterday. (A)
2. My sister **came** home late last night. (A)
3. **Came** (C)
4. A, B, C **were** tired when I **came** home. (B)
5. A **did** go to school two days ago. (C)

Feel free to ask if you need further assistance!