16. He went to the bookstore and bought _____.
A. Score books B. scores books C. score of books D. scores of books
17. We should stick to the principles and be ______ as well.
A. flexible B. determined C. patient D. relaxed
18. Mary is blind. If she ______ the bright world now, she would be full of joy.
A. will see B. can see C. could see D. has seen
19. We must ______ our unity in protection of blue sky from pollution.
A. lose B. strengthen C. divide D. ban
20. The school students have to ______ the neighboring noise made by the wedding company.
A. make up with B. keep up with C. put up with D. fill up with
21. How to ______ the quality of food has become a focus now.
A. advocate B. guarantee C. possess D. measure
