在英语越发普及的21世纪，英语成了大学生的必修课。为帮助大家掌握权威的英语知识，特提供以下资料：
1. The political future of the president is now hanging by a __.
A thread
B cord
C string
D rope
2. The question is still__ discussion.
A in
B by
C for
D under
3. We managed to reach the top of the mountain, and half an hour later we began to __.
A ascend
B descend
C decline
D plunge
4. To survive in the intense trade competition between countries, we must__ the qualities and varieties of products we make to the world-market demand.
A improve
B enhance
C guarantee
D gear
5. There has been a __ lack of communication between the union and the management.
A regretful
B regrettable
C regretting
D regretted
谜底：
1-5ADBDB
1.选A 四个选项都有“绳子”这个意思，但只有thread和hang by组成习语：hang by a thread千钧一发，危在夙夜迟早
2.选D be+ prep+n(表动作的名词)来暗示“被动”而under discussion是习惯搭配
3.选B descend 指人，物体从某一高度/斜面上“下来/降”On turning the corner, we saw that the road descended sharply.
decline 强调权力，繁荣，成就，健康状况，体力，记忆，数目的“削减，式微”His influence declined after he lost the election.
ascend逐步上升，descend的反义词。We watched the balloon ascend higher and higher.
plunge使俄然前倾或下降The sudden application of the brakes plunged him forward.
enhance 增添，提高The moonlight enhanced the beauty of the scene.
4.选D gear to使……适合，配合We must gear the amount of products we make to the increase in public demand. 此刻来剖析问题问题.题中的To……,是目的状语.而we 是主语, gear.to是谓语,而the qualitiesand varieties of products 是宾语,而we make 是啻滢饰这个宾语的,the world-market demand是宾补.句子的大请安思就是说我们必需按照市场的需求制造商品,才能在市场上安身.
5.选B regrettable 可惜的regretful悔怨的，抱愧的