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。

Tom looks so pale today. He ______ ill.

must be

had to be

should be

shall be

[翻译]汤姆看起来脸色不好，他一定生病了。[解析] A 试题解析：情态动词must表示推测。题目中表示肯定的推测。

Going on a trip into         space must be quite         exciting experience.

/; the 

/; an

the; the 

the; an

考查冠词。句意：太空旅行是令人兴奋的经历。第一空不填，space前面不加冠词，第二空后面的experience作“经历”时是可数名词，表示“一次令人兴奋的经历"。exciting首字母的发音为元音音素，因此应填an。故选B项。

Only then_______ how much damage had been caused.

she realized

she had realized

had she realized

did she realize

“only＋状语”位于句首，整个句子用不完全倒装．此外，由then可确定用过去时态．

It is well-known that crack cocaine is a powerful             drug and users become           to it much more easily if they smoke it.

addicted; addict

addictive; addict

addicted; addictive

addictive; addicted

考查形容词辨析。众所周知可卡因是一种强大的令人上瘾的毒品，如果使用者吸了它更容易上瘾得多。addicted上瘾的，着迷的；addict"shi使沉迷；使上瘾”是动词；addictive “使成瘾的，令人沉迷的”。第一空表示“令人上瘾的”用addictive，故排除A，C项；become addicted to “对....上瘾”，第二空填addicted。故选D项。

With a lot of difficult problems           ,he feels like a cat on  hot bricks.

to settle

being settled

settling

settled

考查非谓语动词。句意： 因为有一大堆难题要解决，他感觉像像热锅上的蚂蚁。本句with +名词+to do sth,动词不定式表示的动作尚未发生或当时看来尚未发生。本句表示“因为有一大堆难题要解决”。故选A项。

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

        bothers me is that I can't keep my mind on the task, but on personal gains or losses.

What

It

That

One

考查主语从句连接词。句意：困扰我的是我不能专注于任务，而是专注于个人得失。此处为主语从句，从句中缺少主语，结合句意表示“困扰我的是”应用what。故选A项。

Perhaps they have experienced something similar and do not want you to           the same pain.

go over

go through

go around

go on

考查动词短语辨析。句意：也许他们有过类似的经历，不希望你经历同样的痛苦。A. go over复习，重温；B. go through经受，通过；C. go around 四处走动，流传；D. go on继续。根据the same pain可知，此处是“经历，经受”的意思。故选B项。

It was last night ________ I saw the comet.

the time

when

that

which

强调句的结构是：It＋be＋强调部分＋that(who)＋主谓句。强调句的连词只有两个，that和who。当强调的部分是人，且为句子的主语时，才用“who”，其余用that。因此选C。

---I think you are different now.

---Of course，times have changed and________.

so have I

so I have

neither have I

neither I have

肯定的陈述句后，跟so+主语+谓语，表示强调：确实…，其主语与前陈述句的主语相同；肯定的陈述句后，跟so+谓语+主语，表示…也…，其主语与前陈述句的主语不同．根据times have changed，可知对另一个"我"说时代也已经变了，用倒装句，本句是现在完成时，含有助动词have，主语为I，在这里还用助动词have完成，故选A．