We must do something useful to _______ pollution.
A. cut off B. cut up C. cut down D. cut in
C
【解析】
句意：我们必须做一切有用的事情来减少污染。cut down意为“减少”；cut off意为“切除”，cut up意为“切碎”，cut in意为“插嘴，干预”，这里是说要“减少”污染，故选C。 Smoking can ________ lung cancer. You had better give it up.
A. work on B. lead to C. take away D. put out
B
【解析】
试题句意：吸烟会引起肺癌。你最好戒烟。A. work on从事；B. lead to引起，导致；C. take away拿走，带走；D. put out扑灭，熄灭。吸烟引发肺癌。故选B。 —There are only a few old city walls left.
—Yeah. Most of them ______ in the 1960s.
A. pulled down B. have pulled down C. had pulled down D. were pulled down
D
【解析】
them指代old city walls，是动作的承受者，所以用被动语态；根据时间状语in the 1960s可知用过去时。 —What are the _______ of bike riding?
— It can help cut down air pollution.
A. advantages B. reasons C. results D. ideas
A
【解析】
句意：-骑自行车的好处是什么？-它能帮助减少空气污染。advantage 意为“优点”； B.原因C.结果D.主意；想法，“帮助减少空气污染”应该是骑自行车的优势/好处advantage，故选A。 — Are you going to _______ any of the events?
— Yes. Maybe long jump and high jump.
A. take part in B. join
C. attend D. join in
D
【解析】
句意：-你将要参加任何活动吗？-是，可能是跳远和跳高。take part in 指参加会议或群众性活动等，着重说明句子主语参加该项活动并在活动中发挥作用，这里参加的是“比赛”，不合适，排除A。join有两个用法：(1)指加入某个党派，团体组织等，成为其成员之一，意为：“参军、入团、入党”等 。(2)和某人一道做某事，其结构为：join sb. in (doing) sth... Many overseas Chinese look forward to________more about their roots in the summer camp．
A. learn
B. be learning
C. learning
D. be learned
C
【解析】
look forward to短语中，to是介词，其后应该用v．-ing形式，因此答案为C。 —Most paper is made________wood．
—Yeah．But most books are made________paper．
A. of；of
B. from；from
C. of；from
D. from；of
D
【解析】
be made from由……制成，从制成品上看不出原材料；be made of由……制成，从制成品上可以看出原材料。 —Are you free now?
—No．I have so many chores________today．
A. do
B. to do
C. doing
D. done
B
【解析】
不定式形式作后置定语。 —________free education，the poor children in my hometown can go back to school．
—So can the children in my hometown．
A. Thanks to
B. Instead of
C. As for
D. Towards
A
【解析】
句意：——多亏了免费教育，我家乡的贫穷孩子们可以重新去上学了。——我故乡的孩子们也是。“多亏了”应该表示为“thanks to”。 （题文）Grandma________us stories when we were very young．
A. used to tell
B. was used to tell
C. is used to tell
D. was used to telling
A
【解析】
本题题意为“我们很小的时候，奶奶常常给我们讲故事”。“过去常常做某事”应该表示为“used to do sth．”，因此答案为A。