13.I’m as busy as a bee;________ you bother me with so many questions now?
A.may
B.must
C.can
D.shall
答案：B
解析：考查情态动词。句意为：我忙得不可开交，为什么你现在偏要拿这么多的问题来打扰我呢?must有时可以表示一种不受欢迎的巧合，指某事发生得不早不迟，就在某个当紧的时候，通常含有不快、不满、心烦、恼火等感情色彩，意为“偏偏，偏要”。
14.—Did you go to the fashion show last week?
—I ________，but I was fully occupied the whole week.
A.must go
B.must have gone
C.would go
D.would have gone
答案：D
解析：考查虚拟语气。根据答语中的“but I was fully occupied”可知，此处是对过去事实的虚拟，应用would have done结构，表示“本来要做某事而实际上未做”，故选D项。
15.It is important to know about the cultural differences that ________ cause problems.
A.must
B.dare
C.may
D.shall
答案：C
解析：考查情态动词。句意为：了解有可能会带来麻烦的文化差异是重要的。此处may表示不确定的推测，意思是“有可能”。
16.—Could I have a word with you，mum?
—Oh，dear，if you ________.
A.can
B.must
C.may
D.should
答案：B
解析：根据答语的第二句话可知“不能把书拿出阅览室”，表禁止，故选D项。
17.My mother is a great cook and we ________ never get enough of her cookies.
A.may
B.need
C.should
D.can
答案：D
解析：句意为：我妈妈是一个很了不起的厨师，我们吃不够她做的饼干。can’t…enough为固定搭配，意为“无论……也不过分”。
18.—I wonder where Peter is.He said he’d be here for lunch.
—Don’t worry!He________be caught in the rush hour.
A.will
B.should
C.can
D.may
答案：D
解析：考查情态动词表示推测。句意为：——我想知道Peter在哪里。他说要来这里吃午饭的。——别担心!他可能遇到上下班高峰期了。may表示事实上的可能性，意为“可能，也许”。
19.—Why，I didn’t get you on the phone.
—We ________football on the playground when you phoned.
A.must be playing
B.must play
C.must have played
D.must have been playing
答案：D
解析：句意为：——嗨，我打电话没找到你。——你打电话的时候我们肯定正在操场上踢足球。表示对过去所发生的事情的肯定推测用must have done的形式，再结合语境可知此处推测的是过去某个时间正在发生的事情，故用must have been doing，故答案为D项。
20.—Why didn’t Henry come?
—He ________ except he didn’t have time.
A.would have come
B.will come
C.would come
D.will be coming
答案：A
解析：句意为：——Henry为什么没来?——他本来要来的，只是他没有时间。except从句表达的是过去时陈述语气，主句为与过去相反的虚拟语气。
21.He hesitated for a moment before kicking the ball，otherwise he________a goal.
A.had scored
B.scored
C.would score
D.would have scored
答案：D
解析：这是otherwise 引出的含蓄虚拟语气，再根据前面的hesitated 可进一步知道这是与过去事实相反的虚拟语气，由此可推知答案选D。
22.It is hard for me to imagine what I would be doing today if I________in love，at the age of seven，with the Melinda Cox Library in my hometown.
A.wouldn’t have fallen
B.had not fallen
C.should fall
D.were to fall
答案：B
解析：句意为：要不是在七岁时就迷上了Melinda Cox 图书馆，我真不能想象我如今会在做什么。此题涉及错综时间虚拟条件句，主句与现在事实相反，条件句与过去事实相反。
23.—My uncle suggests I ________ abroad.
—I would rather you ________ at home.
A.go;stay
B.went;stayed
C.go;stayed
D.went;stay
答案：C
解析：suggest作“建议”讲，谓语动词用should do或do。would rather后跟的从句也用虚拟语气，叙述与现在、将来事实相反时，用过去时;叙述与过去事实相反，用过去完成时。
24.It’s useless envying others their success.It’s time you ________ hard.
A.must work
B.went to work
C.work
D.worked
答案：D
解析：此处考查固定句型中虚拟语气的使用。It’s time that…中，从句中动词用过去时或should do。
25.They ________ two free tickets to Canada.Otherwise，they’d never have been able to afford to go.
A.had got
B.got
C.would have got
D.get
答案：B
解析：otherwise相当于一个虚拟条件，是对真实情况的相反的假设，由此我们可以推断出：题干中otherwise前面的内容应是真实的，故空白处应该是陈述语气;再结合句意可知，此处讲的是过去的事情，因此用一般过去时。