Here are the best options for each blank:

7. Many of his test results were **unsatisfactory** because of his poor attention in class.
**Answer: B. unsatisfactory**

8. Eagles are protected by law, but they are still **threatened** with extinction.
**Answer: C. threatened**

9. **Biology** is a science of living things on the earth.
**Answer: D. Biology**

10. The robbers ran away and **took away** a lot of valuable jewels.
**Answer: B. took away**

11. We always **take** lots of photos while we're on holiday.
**Answer: A. take**

12. She received a(n) **award** from the head master for her outstanding performance in learning.
**Answer: A. award**

13. The **majority** approved of the plan. It was finally cancelled.
**Answer: B. majority**

14. They built canals to **irrigate** the desert.
**Answer: A. irrigate**

15. If you want to buy something old and inexpensive, you should go to a **antique** shop.
**Answer: B. antique**

16. If he **had invited** the teacher, she would have come, I think.
**Answer: C. had invited**