41. she ought to stop work; she has a headache because she _a_ too long.
a has been reading b had read c is reading d read
had read 过去完成时要与一般过去时搭配。
has been reading 现在完成进行时：指某行为从过去一点到现在一直在进行。
42. niagara falls is a great tourist _b_, drawing millions of visitors every year.
a attention b attraction c appointment d arrangement
tourist attraction 旅游胜地; attention n. 注意力; appointment n. 委任的职位，约会;
date n. 日期，约会，枣;表示约会时指的是异性之间的私人约会。 arrangement n. 布置，安排
blind date 两人第一次见面的约会。 appointment 指公事性质的，比较正式的约会。
43. i don't mind _b_ the decision as long as it is not too late.
a you to delay making b your delaying making
c your delaying to make d you delay to make
mind 后要加动名词; delay v. 耽搁，延误(后面也要加动名词)
45. corn originated in the new world and thus was not known in europe until columbus found it _a_ in cuba.
a being cultivated b been cultivated c having cultivated d cultivating
46. the sale usually takes place outside the house, with the audience _c_ on benches, chairs or boxes.
a having seated b seating c seated d having been seated
注意：seat是及物动词，及物动词用主动形式，后面要直接加宾语。
be seated please. 请坐。 英语中只有及物动词才有被动语态。
47. this kind of glasses manufactured by experienced craftsmen _b_ comfortably.
a is worn b wears c wearing d are worn
当wear表穿戴时，而句子的主语是被穿戴的东西时，wear是不及物动词，没有被动语态。
65. the coming of the railways in the 1830s _a_ our society and economic life.
a transformed b transported c transferred d transmitted
字根trans在四级中着重考的含义是“从一个地方到另一个地方”。
transform 改革，变革，改变; transport 运输; transfer 转移，移动;
transmit 传送，播送;疾病的传染，传播; transplant 移植。
48. some diseases are _d_ by certain water animals.
a transplanted b transformed c transported d transmitted
49. wouldn't you rather your child _b_ to bed early?
a go b went c would go d goes
would rather的两种用法：1 would rather + 动词原形;
2 would rather + 句子(句子谓语动词用一般过去时体现虚拟语气)。
50. although anne is happy with her success she wonders _b_ will happen to her private life. [wonder后面要加疑问词]
a that b what c it d this
51. the words of his old teacher left a _c_ impression on his mind. he is still influenced by them. [lasting adj. 持久的，永久的; liberal adj. 开明的，心胸开阔的]
a long b lively c lasting d liberal
52. mike's uncle insists _d_ in this hotel.
a staying not b not to stay c that he would not stay d that he not stay
insist的两种用法：1 insist on … 坚持，坚决要求;
2 insist + that引导的从句(从句谓语动词为[should] + 动词原形)
53. we agree to accept _d_ they thought was the best tourist guide.
a whatever b whomever c whichever d whoever
they thought是插入语，可以不看; tourist guide 导游。