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

There's no simple solution          this problem.

of

for

to 

about

考查介词。句意：这个问题没有什么简单的解决方法。此处是短语“

the solution to....的解决方法”，应用介词to。故选C项。

If you want to catch the first bus you'd better         for the bus station immediately.

set up

set about

set down

set off

考查动词短语辨析。句意：如果你想赶上第一班公交车，你最好马上动身去车站。A. set up建立；B. set about开始做.....;C. set down 记下；D. set off 出发，动身。结合上文If you want to catch the first bus you'd better可知此处指“动身，出发”，应用set off。故选D项。

It's really           to know that there're only seven bones in giraffes' long necks.

amazingly

amazed

amazing

amazement

考查形容词辨析。句意：知道长颈鹿的长脖子上只有7块骨头，真是令人惊讶。分析句子结构可知，is是系动词，空格处需填形容词作表语。主语是It,指物，表示“令人惊讶的”，应填amazing。故选C项。

The number of deaths from a powerful typhoon sweeping across China’s east coast          to 30 on Sunday.

raised

rose

aroused

arose

考查动词词义辨析。句意：周日，异常席卷中国东海岸的强台风造成的死亡人数上升到30人。A.raised提升，增加； B.rose 增加（原形是rise）C.aroused激起，引起；D.arose发生，出现。分析句子可知，这里要表达“人数增长到30”，而A,B选项中，raise是及物动词，后面直接接宾语，而rise为不及物动词，用“rise to”表示“增长到.....”。故选B项。