"No,I really must leave," I said firmly.

VOA: special.2009.07.04

One question is this: Is it really true that in order to think about the perfectly straight, I must have somehow, somewhere at some point come up against, had direct knowledge of, the perfectly straight?

一个问题是,难道真的说,为了想象一条完美的直线,我必须,在某处直接碰到,并直接了解一条完美的直线吗

耶鲁公开课 - 死亡课程节选

Oh really? I imagine that it must be very difficult to drive in a big city like New York.

是吗？在大城市开车肯定会比较困难，比如在纽约。

Do you ever实战 - SpeakingMax英语口语达人