become用作连系动词的用法look, sound, smell, taste, feel的用法特点become的用法appear的用法如何区分半连系动词非谓语动词的用法比较非谓语动词非谓语动词的否定式非谓语动词语法非谓语动词的时态和语态非谓语动词作状语的用法谓语动词与非谓语动词的用法区别非谓语动词例题及十大解题原则间接引语中的条件句come doing sth 与 go doing sth 的用法非谓语动词作宾语to do/doing/done非谓语动词作宾语例句非谓语动词特殊用法谓语动词用单数形式的情况并列连词与并列结构