Question

Try not to cough more than you can___since it may cause problems to your lungs

A.check B.allow C.stop D.help
详解下，为什么用help

Answer 1

你好，看一下以下例句你就懂了
Don't lose more than you can help at the casino.你赌博可别把裤子都输掉了。
Don't tell him more than you can help.点到为止。
Don't change it any more than you can help (that is, "any more than you have to" ).除非万不得已，否则就不要再改变什么了（也就是说，“除非你不得不”）。

文中意思，不到万不得已，别咳得太多，因为会造成肺部问题

追问

If we __now to protect the environment,we'll live to regret it.
A.hadn't acted B.haven't acted C.don't act D.won't act
如何区分B,C选项

追答

B.haven't acted 是现在完成时，很明显，保护环境是当下及以后要做的事，而不是已完成的

所以要选c
大意： 如果我们现在不采取行动来保护环境，我们将来就会活在后悔之中

Answer 2

help 意思是 禁得住；
此外，

can't help doing sth, 意思是禁不住做某事

Answer 3

check检查　allow允许　stop停止　help避免
把每个词都带进去翻译一下，就是：既然咳嗽可能给你的胃带来问题，试着不要比你能避免的咳嗽得更多