Sure, I'll help you with the answers and explanations for each question.

11. You talk too ___ and you often do too ___ tricks in class.
- A. much/many
- B. little/much
- C. little/much
- D. many/much

**Answer: A. much/many**
- Explanation: "Much" is used with uncountable nouns (talk), and "many" is used with countable nouns (tricks).

12. ___ the countries in that area of the world, perhaps Nigeria has the most potential.
- A. Of all
- B. All of
- C. Most
- D. A great deal of

**Answer: A. Of all**
- Explanation: "Of all" is used to compare Nigeria with all the other countries in that area.

13. After doing the shopping, she had got ___.
- A. a few money left
- B. little money left
- C. some left of money
- D. several of money left

**Answer: B. little money left**
- Explanation: "Little" is used with uncountable nouns (money) to indicate a small amount.

14. The examination was not very difficult, but it was ___ long.
- A. so much
- B. too much
- C. very much
- D. much too

**Answer: D. much too**
- Explanation: "Much too" is used to emphasize that something is excessively long.

15. Increasing ___ of fruit in the diet may help to reduce the risk of heart disease.
- A. the amount
- B. an amount
- C. the number
- D. a number

**Answer: A. the amount**
- Explanation: "Amount" is used with uncountable nouns (fruit) to indicate quantity.

16. While Southern California is densely populated, ___ live in the northern part of the state.
- A. a number of
- B. many people
- C. few people
- D. a few of people

**Answer: C. few people**
- Explanation: "Few people" indicates that not many people live in the northern part of the state.