1.They have no choice but----.

1.They have no choice but____.
A.live on bread B.live by bread C.to live on bread D.to live by bread
举例：I have no choice but to tell you the truth.我别无选择,只有告诉你实话.
所以这句,他们别无选择,只能靠面包生活.用but to 然后
live by 靠...过活 live by doing or sth./n.
e.g.Jack lived by writing for a newspaper.
杰克靠给一家报纸写稿来维持生活.
live on
1.靠...生活;以...为食
（动物）以...为食；（人）靠...生活
2.live on靠吃---生活,靠---维持生活
live in
形容词 a.
1.住在受雇之处的
2.(未婚而)同居的
所以是 C
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2.Now we should do all we can ____the Great wall.
A.to prevent B.to preserve C.protect D.protest
B,Now we should do all we can 其实这句话是一体的,我们做我们所能做的“去”保护我们的长城.这里少个“去”去就是to.很好理解吧?比什么语法理解快多了.然后preserve也有保护的意思啦.
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3.It's no good ____.
A.waste a lot of time on nothing
B.to waste a lot of time on nothing
C.wasting a lot of time to complain
D.wasting a lot of time complaning
选D.
It's no good doing sth.是固定句型,"做某事没有用/好处".
类似的：It's no use /useless doingsth.
It's no wonder that (从句）.
There's no doubt that （从句）.
There's no need to do sth.
注意记清楚每个句型后的形式哦!
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4.____the programme,they have to stay there for another 2 weeks.
A.Not completing B.Not completed C.Not having completed D.Having not completed
not having done是非谓语动词中正确的用法,用作状语比较多,如 Not having heard from him
所以是 C
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5.though___money,his parents managed to send him to university.
A.lacked B.lacking of C.lacking D.lacked in
短语：lack of sth.(lack 为名词)
lack sth(lack为动词)
lacking 是非谓语形式
所以lacking of monery 错,lacking money 才对
所以是C
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6.the bell__the end of the period rang,___our heated discussion.
A.indicating;interrupting B.indicated;interrupting C.indicating;interrupted D.indicated;interrupted
个人觉得要ing前面要助词 be所以要从B 和D选咯,然后嘛,选B咯.