语法 介词 + doing 动名词
解释 1、动名词是 V+ing 变成名词 2、动名词都是单数 3、动名词角色：动名词主语，介词后面作宾语
1 作主语 Fishing is my favourite sport. Playing basketball is my favourite sport. Playing basketball with my friends every Sunday is my favourite sport.
2 介词后，作宾语 介词后面用宾语取代，如果是是动词，则加int变成动名词。 I often fish for hours without catching anything. Instead of catching fish, they catch old boots and rubbish.
3 反义词 Some fishermen are unlucky. 有一类形容词前添加 un 这个前缀，就能组成这个词的反义词。 eg: unhappy unpleasant unimportant uninteresting
