C．should take D．must have taken

答案　B

解析　句意为：玛丽本应该接受被提供的这份工作，但是她没有。ought to have done本应该做而未做。

6．American Indians about five percent of the US population.

A．fill up B．bring up

C．make up D．set up

答案　C

解析　句意为：美国印第安人构成了大约5%的美国人口。fill up填满；bring up抚养，提出；make up组成，构成，弥补；set up成立，建立。由句意可知选C。

7．Everyone knows that is dangerous to play with fire, but is difficult is to prevent children from doing so.(015·长沙高一检测)

A．it；it B．it；what

C．what；what D．what；it

答案　B

解析　句意为：大家都知道玩火是危险的，但是阻止孩子们玩火是困难的。分析句子结构可知，第一个空用形式主语it，真正的主语为动词不定式短语to play with fire；第二个空用what引导主语从句，故B项正确。

8．It is known to all that a proper amount of exercise to good health.

A．benefits B．contributes

C．values D．improves

答案　B

解析　句意为：众所周知，适量的锻炼有助于身体健康。benefit使受益；contribute to促成，有助于；value估价，评价，尊重，重视；improve提高，改善；A、C、D三项不与to搭配，故B项正确。

9．With our knowledge practice，we can make contributions to our society.

A．to base on B．basing on

C．based on D．base on

答案　C

解析　考查非谓语动词。句意为：用我们以实践为基础的知识，我们能为社会做出贡献。be based on 以......为基础，此处为过去分词短语作定语，相当于定语从句which is based on practice，故选C项。

10．As we all know，the English language the grammar and vocabulary that people from different countries and cultures brought to Britain.