Here are the corrections for each question:

1. Correction: **C. in** → **on**
Corrected sentence: From at eight until eleven in the morning, Ms. Cobie works **on** the fields with his son.

2. Correction: **D. two-months** → **two-month**
Corrected sentence: My aunt usually has a **two-month** Tet holiday.

3. Correction: **B. unhappy** → **unhappily**
Corrected sentence: Why is Jason talking **unhappily**? Because he is missing his family and his old friends.

4. Correction: **D. to watch** → **watching**
Corrected sentence: The nurse says he should spend a little time **watching** TV.

5. Correction: **A. in** → **is in**
Corrected sentence: Robinson **is in** the class 5C and he always gets on well with his classmates.

6. Correction: **C. hundred** → **hundreds**
Corrected sentence: The public library in the town has **hundreds** of history books.

7. Correction: **D. has** → **is**
Corrected sentence: What does your new neighbor **is**? He has curly hair and brown eyes.

8. Correction: **C. while** → **to**
Corrected sentence: Will you take care of my house **to** we are away?

9. Correction: **B. by the** → **by**
Corrected sentence: I don’t often go to school **by** bus because it takes a lot of time.

10. Correction: **C. at** → **in** (the second instance)
Corrected sentence: My friend has a keen interest **in** geography but he is not good at it.

These corrections aim to enhance the sentences and ensure grammatical accuracy.