高一英语课本中的句子“It is a matter of time before they will discover that

问题描述:

高一英语课本中的句子“It is a matter of time before they will discover that
It is a matter of time________they will discover that John has left.A.before B.when这两个答案该用哪个

选A,我在google上搜了一下“it is a matter of time”,凡是有后半句话的都用的是before,应该是个固定搭配.我认为应该翻译成“早晚”.他们早晚会发现John走了.