C表示建议、要求，命令，请求等含义的名词引导表语从句和同位语从句;常考的有：

　　advice忠告decision，demand，desire，insistence，motion提议

　　necessity必要性order命令

　　preference偏爱，选择proposal，pray恳求

　　recommendation推荐request要求

　　requirement要求resolution决心

　　suggestion劝告，忠告

　　典型例句：

　　1.He ordered that parking be prohibited on Main street during the rush hour

　　2.It is appropriate that some time be devoted to thorough study of the results of the Aoollo mission.