Only time will tell if the treatment has been successful.

　　只有時間才能證明這種療法是否成功。

　　He must be 70 if he's a day!

　　他至少70歲了！

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

　　即使我永遠再也見不到他，我也不在乎！

　　Call me if you have any problems regarding your work.

　　你如果還有什么工作方面的問題就給我打電話。

　　What difference will it make if he knows or not?

　　他知不知道有什么關系嗎？

　　Please let me know how many are coming, if any.

　　請告訴我，如果有人要來的話，有多少？