1.There is no doubt ________ Catherine is fond of dancing, for she always
practices it on weekends.
A. whether B. if C. that D. which
【答案】C。解析：考查同位语从句，句意：毫无疑问Catherine喜欢跳舞，因为她总是在周末练舞。分析句子的结构可知，逗号之后为“for”引导的原因状语从句，逗号之前是主句，主句中结构为"There
is no doubt
that…"意为"毫无疑问…"，连词"that"引导同位语从句解释说明名词"doubt"的具体内容，同位语从句中句子结构和意思已完整，"that"无意义也不充当成分，只起连接词的作用.故C为正确答案。
2.You have seen the girl ________ sister is a Chinese teacher.
A. whom B. of whom C. whose D. of which
【答案】C。解析：此句先行词为the girl，定语从句为sister is a Chinese teacher，二者构成的完整句为The girl’s sister is a Chinese teacher.先行词的’s所有格构成的所属关系结构在从句中作定语。故选C。
3.He found it increasingly difficult to read, ______ his eyesight was beginning to fail.
A. and B. for C. but D. or
【答案】B。解析：此题考查原因状语从句。“his eyesight was beginning to fail”是“he found it increasingly difficult to read”的原因，因此本题应选用可以表示原因的连词for引导原因状语从句。故选B。
4.Mr. Smith used to smoke______, but he has given it up.
A. seriously B. heavily C. badly D. hardly
【答案】B。解析：seriously认真地;badly严重地;hardly几乎不。smoke heavily烟吸得很厉害。为固定说法。故选B。
5.The crazy fans ________ patiently for two hours and they would wait till the movie star arrived。
A.were waiting B.had been waiting C.had waited D.would wait
【答案】B。解析：因为would wait是过去将来时，可见此事发生在过去，再结合for two hours可知，wait这个动作是从过去某一时刻开始一直延续到另一个过去时刻，并且还在等，一直要等到那位影星到来，所以用过去完成进行时：had been doing，因此选B。
6.This machine is very easy ________. Anybody can learn to use it in a few minutes.
A. operating B. to be operating C. operated D. to operate
【答案】D。解析：在句型“主语+be+adj+to do”中，如果这个主语是动词do的逻辑宾语，故用主动表被动，所以选D。