四级英语语法精解（一）

        (2)根据状语的功能选择不同的连词
        Careful surveys have indicated that as many as 50 percent of
        patient do not take drugs ___ directed.(1996.1)
        A. like B. so C. which D. as
        由上下文的意思可以看出，分词所做的是方式状语，连词应该是as。
       
        9) 非谓语动词的体
       
        非谓语动词中分词的体有完成体和进行体，即having done, having been done和being done，完成体只用于做状语的场合，而进行体可以用于做定语和做补足语。
        动名词的体也有having done, having been done和 being done的结构主要用于做主语和宾语的场合。
        不定式的体有to be doing 和to have done，主要用于pretend, happen, seem, appear, be said to等结构中。如：
        ① The man in the corner confessed to _____ a lie to the manager
        of the company.(1997.6)
        A. have told B. be told C. being told D. having told
        having told在句中做介词宾语，表示动作发生在谓语动词之前。
        ② I'd rather read than watch television; the programs seem ____
        all the time.(1997.1)
        A. to get worse B. to be getting worse
        C. to have got worse D. getting worse
        从all the time的使用可以推断get worse是一个渐变过程，所以用不定式的进行体。
        ③ The speech _____ a lively discussion started.(1995.1)
        A. being delivered B. was delivered
        C. be delivered D. having been delivered
        该结构属于独立主格结构做时间状语，状语分词所表示的动作发生在谓语动词之前，所以应该用完成体，答案为D。