11月17日的商务英语大三的选择题2,请给我一些建议,谢谢了.

11月17日的商务英语大三的选择题2,请给我一些建议,谢谢了.
第 1 题： Lincoln proclaimed that the problem of setting free the black slaves should _________ immediate action in the United States.
A. call up
B. call for
C. call on
D. call at
第 2 题： Buyers are aware that the products are not genuine; the forgers do little harm to the genuine manufacturers, because they are aiming ______ completely different markets.
A. at
B. to
C. for
D. on
第 3 题： _____________ the changed circumstances, he urged that the meeting be postponed to the next week.
A. Giving
B. To give up
C. To be given up
D. Given
第 4 题： Respect for the law is the foundation of civilized living. _______ breaks it will be -punished.
A. Who
B. Whichever
C. Whoever
D. Whomever
第 5 题： Teacher can easily ___________ the reasons why it seems more and more difficult for the students to learn English once they have understood the basic structures and patterns of the language.
A.appreciation
B. is aware of
C. understand
D. comprehensive