选B,为了好理解,可以改成:it is very comfortable to sit on the chair,所以介词on是必须的;
选B,不定式表目的
选A,advise sb not to do sth ,建议某人不要做某事,固定搭配;
选B,need此处做实义动词,物在前时,用法,need to be done 或need doing.
选B,为了好理解,可以改成:it is very comfortable to sit on the chair,所以介词on是必须的;
选B,不定式表目的
选A,advise sb not to do sth ,建议某人不要做某事,固定搭配;
选B,need此处做实义动词,物在前时,用法,need to be done 或need doing.