11.
A. worse
B. different
C. separated
D. similar

It is __11__ from a cold, but people can catch it in the same ways -- such as coughing on someone, not washing your hands or sharing a glass with a sick person.

分析：备选项都是形容词，注意词义差异和使用特点。线索：介词from。

Similar adj相像的，相似的；近似的

e.g. My new dress is similar to the one you have.

我的新衣服和你的那件相似。

Separate vt, vi 分开； 离开；隔开，阻隔

e.g. The two children separated at the end of the road.

两个孩子在路的尽头分手了。

e.g. A fence separated the cows from the pigs.

围栏把奶牛和猪分开。

Different adj（常from, to与连用）不同的；相异的；不同类的

e.g. It was very different from modern car races but no less exciting.

它与现代小汽车比赛大不相同,但激动人心的程度却毫不逊色。 

12.
A. curing（*）
B. fighting（*）
C. knowing
D. getting

-- Describe how SARS is spread, but mention that the chance of __12__ SARS is small.

分析：备选项是动词，注意词义差别和在句子中的搭配结构。线索：句意和上下文。或用排除法排除A和B（近义词）。 

13.
A. unless
B. since
C. after
D. while

There is no reason to tell children people are dying of SRAS __13__ they ask. Never use the threat of death as a way to remind kids to wash their hands.

分析：备选项是引导状语从句的连词，注意分句和主句之间的逻辑关系。线索：接下来一句的句意。

Remind vt（常与of, to + inf, that连用）使想起；使记起；提醒

Remind me to write to Mother.

提醒我给妈妈写信。

This reminds me of last year.

这使我想起去年的事。 

14.
A. some
B. their
C. our
D. other

-- Children should be encouraged to trust __14__ parents and other caregivers.

分析：备选项中有代词出现，注意代词的修饰成分和句意。 

15.
A. as
B. except
C. like
D. despite

Explain that many smart people, __15__ doctors and scientists, are working on the problem and looking out for everyones health.

分析：备选项是词义较明确的介词，注意其引导的短语在句子中的语法关系。该介词短语在句子中起举例的作用。

Like prep如同，像，和…一样，例如，诸如

I wish I could sing like her.

我希望能像她那样唱歌。

There are several people interested, like Mr Jones and Mr Simpson.

许多人很有兴趣，诸如琼斯先生和辛普森先生。

feel like想要

look like似乎，好像

work on v.继续工作, 设法说服, 影响

look out v.留神, 照料