if当是否讲引导什么从句

Put your hand up if you need more paper.

若有人还要纸，请举手。

Only time will tell if the treatment has been successful.

只有时间才能证明这种疗法是否成功。

He must be 70 if he's a day!

他至少70岁了！

I don't care if I never see him again!

即使我永远再也见不到他，我也不在乎！

Call me if you have any problems regarding your work.

你如果还有什么工作方面的问题就给我打电话。