1、【题目】heteachertoldthemsincelight________(travel)fasterthansound,lightning________(appear)togobeforethunder.
答案：
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】Matter is the name ________ (give) to everything which has weight and occupies space.
答案：
given
解析：
暂无解析
1、【题目】________ (catch) in the rain, he was wet to the skin.
答案：
Caught (Having been caught,Being caught)
解析：
暂无解析
1、【题目】We were busy ________ (get) things ready for the trial production when he phoned us.
答案：
getting
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
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