1．【答案】D

2．【答案】D

3．【答案】C

4．【答案】D

5．【答案】B

6．【答案】B

7．【答案】A

8．【答案】B

9．【答案】A

10．【答案】A

11．【答案】D

12．【答案】C

13．【答案】C

14．【答案】C

15．【答案】B

16．【答案】D

17．【答案】A

18．【答案】D

19．【答案】B

20．【答案】C