Though ____ the dangers of smoking to their health, smokers still find it hard to give up smoking.

aware of

are aware of

be aware of

考查状语从句的省略：句意：虽然很多经常吸烟的人已经意识到抽烟对他们健康造成了很严重的后果，但是他们仍然发现很难戒烟。Though引导的让步状语从句是省略句，完整的句子是：though smokers are aware of the dangers of smoking to their health。当主从句的主语一致的时候，可以省略从句的主语和be动词，选B

You must have had some moments when you were disappointed. If so, how           you deal with them?

will

did

can

do

考查动词的时态和语态。句意：你一定有过失望的时候。如果有，你是怎么处理的？must have done 表示对过去的事情的推测。可知时态为一般过去时。在特殊疑问句中助动词应用did。故选B项。

I found _____ convenient to shop online at home .

it’s 

that

it

that was

考查强调句。句意：我发现在家网购很方便。这里it指代后面的to shop online。其中的强调句式是：主语+find it +形容词+to do，意为主语发现做某事是...的，故选C。