1.Let’s buy our tickets while I still have ___.

　　A. a little money to leave B. little money left

　　C. a few dollars left D. few dollars to leave

　　【答案】C。B项和D项中的little和few均为否定含义，与句意不符，排除。C项为have sth. left用法，意思是：“还剩下……”。这里have a few dollars left的意思是“还剩下几个美元”，left的过去分词是leave，它的宾语是前面的a few dollars。句意为：我们买票吧，尽管我们这只剩几美元了。while：尽管。

　　2. We shall ask for samples ___ and then we can make our decision.

　　A. to be sent B. being sent C. to sent D. to have been sent

　　【答案】A本句考查非谓语动词做宾语补足语，因为是将来式，所以用动词不定式做宾补，又因为宾语和宾语补足语之间是逻辑上的动宾关系，因此用动词不定式的被动。本句的意思是：“我们要求把产品的样品送来，然后我们可以做出决定。”

　　3. Some cities have passed laws that allow coal and oil ____ only if their sulfur content is low.

　　A. burning B. to burn C. being burned D. to be burned

　　【答案】D。本题考查的是allow sth. to be done，主动形式是allow sb to do sth.此处是允许人们在硫含量低的情况下燃烧煤和石油，所以它们是被燃烧，用被动。

　　4. Mother warned the electric lamp.

　　A. not to touch B. him not to touch C. him not touching D. him not touch

　　【答案】B不定式的否定式。warn sb.. not to do sth..属于固定搭配。意为“警告某人不要做某事”。

　　5. Don't leave the water ________ while you brush your teeth.

　　A. run B. running C. being run D. to run

　　【答案】B。别让水一直流着。