71 题首选after或when，当然没有选if亦可。72题首选content，没有选information当然可以。不可选 context，那是理解的依据，而非目的。73从句中motivated推知自然是good，当然ideal更好。74是代指单数名词的代词，应是 one；句中后半立即验证。75题一想就知不是grades(或marks、scores之类，美国大学多不给具体分数，而是打出等级，最高是A+)，看选项立即想出原来是learning，是为了学习。76从与后半句对比立即得出with。77对照文章首句立即可得答案，看选项对比排除亦可。78看上句最后一词便知。79看后有说no的冲动，立即感觉有点绝对，改为little，一看选项立即选取中minimum。82表递进，自然是 especially，一看选项，选同义词particularly。83注意source与origin(有的辅导书解释欠妥)，source类比于 fountain，origin是指遥远时空的起源，如The origin of this custom is unknown. 我们注意到 selections和collections面都太窄了。84选个与suggest属一类的后面引起宾语从句其中用虚拟语气的情形，看选项非 prefer莫属。85选too，表嫌其过分，语气正好恰合。86教授自然要教学，当选besides。87表因果，首选consequently，没有次选therefore亦可。88除教学外，还要管行政、搞研究，时间自然是有限的(limited)。89首选consult，次选contact，看选项没有选approach也非常好，居然有annoy晕倒。90题中or与前面的either连用。
       
        此篇一气呵成，上下文联系极强。此中解题方面颇多，不一而足。多处选项在设计时为调整难度本来就有不少近义词的置换，在此问题上大家对词汇的敏感度要下点功夫喔，这与阅读中的置换原则有关系啊。
       
        [答案]
       
        71. A 72. D 73. B 74. B 75. C 76. D 77. C 78. C 79. B 80. A
       
        81. D 82. A 83. C 84. D 85. A 86. D 87. B 88. B 89. C 90. A
       
        [补充练习，请下载，建议时间——12分钟]
       
        In the month of September, in Britain, you may see large numbers of birds 71)________ on roofs and telegraph wires. These birds are swallows. They are 72)________ together because, very soon, they will be flying 73)________ to much warmer lands, where they will find 74)________ the small flying insects on which they 75)________. There are no such insects 76)________ in Britain during the winter; it is 77)________ cold for them.
       
        The swallows settle, fly, swoop, and 78) ________ again. This they do many times, for they are making short 79)________ flights in order to be fit for the long journey 80)_______ them.
       
        81) ________ of these migrating birds leave Britain in the autumn. They fly 82)________ for hundreds of miles 83)________ they reach the warm lands of Africa. But not all the birds get there, for many of them perish in the stormy weather they meet with 84)________.
       
        In the spring of the following year they 85) ________ the long and tiring journey back to Britain. They return to the identical barn or tree in the 86)________ district which they had left the 87)________ autumn. How do these birds find their 88)________ there and back over such vast distances? Nobody knows exactly 89)________, but it has something to do 90)________ winds and air currents.
       
        71. A. being perched B. perched C. being perching D. be perched
       
        72. A. gathering B. assembling C. waiting D. forming
       
        73. A. to south B. the south C. to southwards D. south
       
        74. A. great number of B. a great deal of C. plenty of D. numerous
       
        75. A. feed B. are fed C. eat D. rely
       
        76. A. near B. about C. nearby D. over
       
        77. A. too B. a bit C. very D. much
       
        78. A. fly off B. swoop C. settle D. turn back
       
        79. A. practical B. practicing C. practice D. practised
       
        80. A. in advance B. ahead of C. in front of D. in front
       
        81. A. Swarms B. Herds C. Flocks D. Schools
       
        82. A. firmly B. stoutly C. harshly D. steadily
       
        83. A. until B. before C. when D. as
       
        84. A. in the way B. on the way C. half the way D. all the way
       
        85. A. have B. fly C. find D. make
       
        86. A. old B. original C. familiar D. identical
       
        87. A. before B. previous C. above D. former
       
        88. A. way B. path C. course D. route
       
        89. A. why B. when C. how D. what
       
        90. A. against B. away C. for D. with
       
        [补充练习答案]
       
        71. B 72. A 73. D 74. C 75. A 76. B 77. A 78. C 79. C 80. B
       
        81. C 82. D 83. A 84. B 85. D 86. D 87. B 88. A 89. C 90. D