Question

【題目】The bell rang _________ the teacher was explaining the experiment to the students.

A. until B. before C. while D. after

Answer 1

【答案】C

【解析】句意“老師正向?qū)W生們解釋這個(gè)實(shí)驗(yàn)，下課鈴聲響了。”until直到；before在……之前；while表示當(dāng)……時(shí)候，after在……之后。此處表示當(dāng)老師正講解實(shí)驗(yàn)時(shí)，鈴聲響了，故用連詞while，故選C。