"I wasn't a very good scholar in school."—"Then why did you become a teacher?"

“我在学校时成绩不是很好。”— “那你为什么当老师呢？”

《柯林斯英汉双解大词典》

Then why not work abroad for a year or two?

那为什么不去国外工作一两年呢？

youdao

Then why don't we meet outside the library at 4:15?

那我们4点15分在图书馆外见面好吗？

youdao

"Then why did you make me search the apartment again?" he shouted.

VOA: special.2009.12.26

Well, if that's the right thing to say about the France case, then why not say the same thing about the near-death experience case?

如果关于法国的例子是对的,那为什么关于濒死体验,我们就不能得出相同的结论呢

耶鲁公开课 - 死亡课程节选

And, if you felt you were convinced by my reading of that iconography in these passages, then you want to think about why that's convincing.

如果你觉得我读的,片段中的形象很有说服力，那么你们去想想会什么会信服,作为读者。

耶鲁公开课 - 1945年后的美国小说课程节选

If my story helps people to understand that their money can help--it helped me--then why not?

FORBES: Hitting Close to Home

Then why not just project a larger image onto a larger screen in the first place?

FORBES: Connect

If investors are willing to pay fees for poor performance, then why bother to improve?

FORBES: Financial Sector Funds And ETFs Need Less Citi, More Discover