When            to someone,I usually say, "Pleased to meet you."

introduce

introduced

introducing

am introduced

考查过去分词和省略。句意：当我被介绍给别人时，我通常会说：“很高兴认识你”。根据句子结构可知，本句是when引导的时间状语从句，原句when I am introduced to someone,这里当从句主语与主句主语一致时，并且从句的谓语动词有be这时从句的主语与be同时省略，所以空格处introduced。故选B项。

Since this accident has nothing to do with him, he seems no way             .

to be blamed

to blame

blame for

to blame for

考查固定用法。句意：既然这次事故与他无关，他似乎也就无可指责了。短语sb to be blame“某人该受责备，某人应该负责”，为固定搭配，没有被动语态。故选B项。

As crossing

While you cross

While crossing

Cross

这题考查时间状语从句的省略式，当主从句的主语一样时，可以省略从句的主语和be动词，这题的while crossing就省略了you are，句意是：当你过马路时，别忘了两边看看。选C。

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

Mary never does any reading in the evening, ______.

so does John 

John does too

John does not to

neither does John

主句用never，后面的倒装句相应的用nor或者neither，用完全倒装形式表示后者与前者情况相似。

"Society" is a(n)              term;it may mean much or nothing.

autonomous

ambiguous

fragrant

fragile

考查形容词词义辨析。句意：“社会”是一个模棱两可的词；它可能意味着很多，也可能没有意义。autonmous 自治的；ambiguous模棱两可的；fragrant芳香的；fragile脆弱的。结合后文it may mean much or nothing可知，空格处填ambiguous模棱两可的。故选B项。

_______ by keeping down costs will Power Data hold its advantage over other companies.

Only  

Just 

 Still  

Yet

考查倒装句式。句意：只有通过降低成本，Power Data才能比其它公司更有优势。A只有；B仅仅；C仍然；D然而。Only加副词、介词短语或时间状语，放句首时，用部分倒装。故选A。

Every evening after dinner, if not ________ from work, I will spend some time walking my dog.

being tired

tiring

tired

to be tired

考查省略句。当状语从句的主语和主句主语一致，且状语从句中有be动词的时候，可以把状语从句的主语和be动词一起省略，本题if后面省略了I am，句意：每天晚上吃完晚饭以后，如果不是很累，我就会花点时间来遛狗。故C正确。