I was at nine o’clock ______ I heard some terrible noises upstairs.

题目

I was at nine o’clock ______ I heard some terrible noises upstairs.
It was seven o’clock _______ I was standing under the Big Ben

答案

when 我听见楼上发出恐怖的声音时是9点 (后面用的是一般过去时)
while 7点时我正站在大本钟下.(后面用的是过去进行时)