1、【题目】heteachertoldthemsincelight________(travel)fasterthansound,lightning________(appear)togobeforethunder.
答案：
解析：
1、【题目】________(fail)severaltimes,theyneedsomeencouragement.
答案：
解析：
1、【题目】He asked me whether my brother ________ (fly) to Beijing.
答案：
had flown
解析：
暂无解析
1、【题目】I shall never forget ________ (meet) the late Premier Zhou during his inspection of our factory.
答案：
meeting
解析：
暂无解析
1、【题目】He fell asleep immediately last night; he must ________ (be) very tired.
答案：
have been
解析：
暂无解析
1、【题目】Agreatnumberofsmallpowerstations________(setup)intheircounty sinceliberation.
答案：
解析：
1、【题目】Those who’d like to visit the exhibition ________ (sign) your names here.
答案：
sign
解析：
暂无解析
1、【题目】Some molecules are large enough ________ (see) under the electronic microscope.
答案：
to be seen
解析：
暂无解析
1、【题目】A great number of small power stations ________ (set up) in their county since liberation.
答案：
have been set up
解析：
暂无解析
1、【题目】A beam of light will not bend round corners unless ________ (make) to do so with the help of a reflecting device
答案：
made
解析：
暂无解析
1、【题目】Somemoleculesarelargeenough________(see)undertheelectronicmicroscope.
答案：
解析：
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