实例：The oxidation of exhaust gases is one of primary sources of the world’s pollutions. The brown haze that is poised over some of the world’s largest cities is properly called photochemical smog.

The word poised in this sentence is closest in meaning to__

A. interacting B. sitting C. blowing D. poisoning

首先从搭配关系上可以排除interacting ,因为interact的搭配是with。然后可以从上下文关系排除blowing，因为blow over就吹走了不会有smog。同时D选项的poisoning在作为及物动词的时候才有pollute的含义，替换到本句中式不及物的用法只有一种含义表示投毒也不符合，所以选B。