1．【答案】D

2．【答案】C

3．【答案】C

4．【答案】C

5．【答案】D

6．【答案】D

7．【答案】C

8．【答案】B

9．【答案】D

10．【答案】A

11．【答案】B

12．【答案】A

13．【答案】C

14．【答案】C

15．【答案】A

16．【答案】C

17．【答案】D

18．【答案】C

19．【答案】B

20．【答案】D