口语，“如果拿不准”用英语怎么说？if in doubtused when advising someone what to do if they are uncertain about something当某人对某事不确定时，建议他做某事时就用这个短语；翻译为“如果不确定的话，如果拿不定注意的话”A: When I go to the shop, should I lock the door, or leave it open?当我去买东西的时候，我应该锁门，还是让门开着?B: If in doubt, lock the door. You dont want somebody to burgle you.如果拿不准，就把门锁上。你总不希望有人偷你的东西吧。