当某人告诉你的事令你非常惊讶或者觉得不可能发生时可以用这个问句来回答
You've flown to Paris three times just this month? Is that a fact? 你这个月已经飞去巴黎三次了？这是真的吗？
you would not believe
用在你要告诉其他人某件不寻常或令人惊讶的事的时候
You would not believe who I met this afternoon! 你绝对无法相信我今天下午遇见了谁！
of all things/people/places
用来表达对于某件事竟会涉及到某地/某物/某人的惊讶之情
Now she's chosen to live in Alaska, of all places! 现在她竟然选择定居在阿拉斯加！
who would have thought...?
用来表达你对某件事感到惊讶
Who would have thought that John would get married? 谁能想到John竟然会结婚？