41. Jean did not have time to go to the concert last night because she was busy _C_ for her examination.
A to prepare B to be prepared C preparing D being prepared
be busy doing sth. 忙于做某事
42. Five minutes earlier, _A_ we could have caught the last train.
A and B but C or D an order
and 在这里表示一种结果，翻译成 那么 。只有两种情况下and才会这样翻译：
省略句 + and + 句子; 2. 祈使句 + and + 句子。
43Turn on the television or open a magazine and you _B_ advertisements showing happy balanced families.
A are often seeing B will often see C often see D have often seen
44. I cannot give you _D_ for the type of car you sell because there is no demand for it in the market.
A an expense B a charge C a purchase D an order
order n. 定购，订单; purchase n. 购买。
45. By the end of this month, we surely _C_ a satisfactory solution to the problem.
A have found B will be finding C will have found D are finding
如果一个句子的时间状语是由by引导的，则时态要选择完成时态。
将来的行为在将来的某个时间之前就已完成用将来完成时。
solution to a problem 一个问题的解决方案。
46. Mr. Wilson said that he did not want to _A_ any further responsibilities.
A take on B get on C put up D look up
take on 承担; take on responsibility 承担责任。
47. Having no money but _B_ to know, he simply said he would go without dinner.
A not to want anyone B not wanting anyone C wanted no one D to want no one
dinner n. 正餐; supper n. 夜宵，晚餐; breakfast n. 早餐; lunch n. 午餐;
brunch n. 早午餐。
48. We desire that the tour leader _A_ us immediately of any change in plans.
A inform B informs C informed D has informed
desire v. 要求，表要求时后面加句子要用虚拟语气， + 动词原形。
其他同样用法的词还有ask, demand, request, require.
49. Not _B_, the process of choosing names varies widely from culture to culture.
A obviously B surprisingly C particularly D normally
not surprisingly 一点也不奇怪。 vary vi. 变化。
vary from to 从一种形式变化到另一种形式。vary between and 在两者之间进行变化。
50. 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