简述与传统的分离技术相比较，PF-2D的优点。

简述我国刑法揭示的犯罪的法律和社会特征。

第二节 完形填空（共20小题，每小题1.5分，满分30分）

阅读下面短文，掌握其大意，然后从36---55各题所给的四个选项（A、B、C、D）中，选出最佳选项，并在答题卡上将该项涂黑。

There was a woman in Detroit, 36  had two sons. She was worried 37  them, especially 38 younger one, Ben, because he was not doing well in school. Boys in his class 39  jokes on him because he seemed so 40 . The mother 41 that she would herself get her sons to do 42  in school. She told them to go to the Detroit Public Library to 43 a book a week and do a book report for her.

One day, in Ben’s  44,  the teacher held up a rock(岩石)and asked if anyone 45  it. Ben put up his hand and the teacher let him 46.  “Why did Ben raise his hand?” all of his 47 whispered (低声耳语) and wondered. “He 48 said anything. What could he possibly want to say?”

Well, Ben not only 49  the rock, but also said a lot about it. He 50 other rocks in its groups and even knew 51 the teacher had found it. The teacher and the students were 52  .Ben had learned all this from doing one of his book 53.

Ben later went on to the 54  of his class. When he finished high school, he went to Yale University and 55 became one of the best doctors in the United States.

36.            A. which                     B. who                    C. that                    D. whom

37.            A. on                          B. with                    C. about                  D. in

38.            A. the                         B. an                       C. a                        D. /

39.            A. played                    B. spoke                  C. got                     D. showed

40.            A. clever                     B. hard                    C. slow                   D. quick

41.            A. seemed                   B. decided               C. answered             D. told

42.            A. well                      B. bad                     C. right                   D. good

43.            A. see                         B. find                    C. read                    D. buy

44.            A. class                       B. room                  C. office                  D. lab

45.            A. told                        B. knew                  C. wrote                  D. said

46.            A. think                      B. leave                   C. ask                     D. answer

47.            A. classmates               B. students               C. teacher                D. mother

48.            A. always                    B. ever                    C. sometimes           D. never

49.            A. found                     B. played                 C. knew                  D. heard

50.            A. said                        B. told                    C. called                 D. named

51.            A. whether                  B. what                   C. where                 D. why

52.            A. afraid                     B. surprised             C. worried               D. unhappy

53.            A. pictures                  B. exercises             C. shops                  D. reports

54.            A. top                         B. end                     C. back                   D. front

55.            A. at first                    B. at the end            C. at last           D. now

什么是地理环境的整体性及其表现？

从银杏中分离出的一类具有扩张冠状血管和增加脑血流量作用的成分是（）。

A.萘醌

B.三萜

C.黄酮醇

D.香豆素

E.生物碱

根据钢丝的耐弯折次数，将钢丝韧性等级分为：（）

A、特级

B、I级

C、II级