例题分析：15.It is politely requested by the hotel management that radios ______ after 11 o'clock at night.

　　A. were not played 　　B. not be played

　　C. not to play 　　　　D. did not play

　　全句意思是：“旅馆管理部门恳请客人晚上11点后不要打开收音机”。句中的谓语动词request(请求)所引出的从句应当用虚拟语气，即动词原形或“should+动词原形”。本句的主语从句中，主语radio是谓语动词play 的客体，谓语应当用被动语态。所以，答案是C) not be played。在上述这类句子中不能用动词过去时形式表示虚拟语气，所以A)不正确。选项B) not to play是动词带to的不定式，不能在句中作谓语。选项D)did not play也是动词play的过去时形式，同样不能在本句中作为虚拟语气来使用。而且，它是主动语态形式，而本题要用被动语态。

　　练习：

　　16). The chairman requested that .

　　[A]the members studied more carefully the problem

　　[B]the problem was more carefulnessly studied

　　[C]with more carefulness the problem could be studied

　　[D]the members study the problem more carefully

　　17). The committee recommends that the matter at the next meeting .

　　[A]would be discussed

　　[B]will be discussed

　　[C]be discussed

　　[D]may be discussed

　　18). The doctor insisted that his patient .

　　[A]that he not work too hard for three months

　　[B]take it easy for three months

　　[C]taking it easy inside of three months

　　[D]to take some vacations for three months