29. Features such as height, weight, and skin color _B_ from individual to individual and from face to face.
A change B vary C alter D convert
individual n. 个人，个体； individualism n. 个人主义。
44. The hope, goals, fears and desires _D_ widely between men and women, between the rich and the poor.
A alter B shift C transfer D vary
50. A man escaped from the prison last night. It was a long time _A_ the guards discovered what had happened.
A before B until C since D when
It + 系动词 + 一段时间 + before引导的句子 在…之前花费多少时间。
54. Scientists say it may be five or ten years _D_ it is possible to test this medicine on human patients.
A since B when C after D before
51. In the experiment we kept a watchful eye _D_ the developments and recorded every detail. [keep a watchful eye on 密切主意，留神]
A in B at C for D on
52. There's little chance that mankind would _D_ a nuclear war.
A retain B endure C maintain D survive
retain vt. 保持，保留； endure v. 忍受； maintain vt. 维持，保持，坚持认为；
survive vi. 生存； vt. 活过 … （宾语为某种灾难）。 survive a flood 活过一场洪水。
前缀sur表示过 … ，外，超； vive 表示生活，强调活着。
54. They usually have less money at the end of the month than _C_ at the beginning.
A which is B which was C they have D it is
less … than句子前后要平衡结构。
55. In the course of a day students do far more than just _A_ classes.
A attend B attended C to attend D attending
far more than 远远多于，远不止于；也要句子前后平衡结构。
56. The French pianist [n. 钢琴师] who had been praised very highly _C_ to be a great disappointment.
A turned up B turned in C turned out D turned down
turn up 后面不加宾语表示出现，后面加宾语表示将声音调高，调大；
turn in + 宾语 上缴，交出； turn down 将声音调低，调小；拒绝；
refuse sb. 指直接的回绝； turn sb. down 则指委婉的拒绝；
turn out + 动词不定式 最终证明是，结果是。
57. Many difficulties have _B_ as a result of the change over to a new type of fuel.
A risen B arisen C raised D arrived
因本句未加宾语，估不应选不及物动词，可排除C项； arrive vi. 到达，抵达；
rise vi. 升起，升高（侧重指旗帜或太阳升起）；数量的增高（侧重指水位、价位）；
the sun rises in the east and sets in the west 太阳东升西落。
arise vi. 升起，升高，出现，发生（经常与抽象名词联用）。
Provide a Better Life for Senior Citizens Now we have a growing population of senior citizens. To ensure happy lives for them has become a focus of attention. Our traditiona
Passage Twenty-five (Exploration of the Titanic) After resting on the ocean floor, split asunder and rusting, for nearly three-quarters of a century, a great ship seemed to