_______, they made for the classroom in a hurry.A. With only three minutes to goB. There were only three minutes leftC. As only three minutes to goD. Only three minutes were left

步骤 1：分析句子结构
句子的主干是 "they made for the classroom in a hurry"，表示他们匆忙地前往教室。前面的部分需要一个非谓语动词短语或介词短语来补充说明时间背景。

步骤 2：分析选项
A. With only three minutes to go：表示“只剩下三分钟”，是一个介词短语，可以用来补充说明时间背景。
B. There were only three minutes left：是一个完整的句子，不能直接用作句子的开头。
C. As only three minutes to go：as引导的从句，但to go后面缺少主语，语法不正确。
D. Only three minutes were left：是一个完整的句子，不能直接用作句子的开头。

步骤 3：选择正确答案
根据句子结构和语法，选项A是正确的，因为它是一个介词短语，可以用来补充说明时间背景。