be busy doing sth 为什么是动名词有神马规律吗
be busy doing sth 为什么是动名词有神马规律吗
be busy doing sth 中的busying是动名词还是现在分词,这里面得busy是形容词还是动词?
有没有be busy with doing sth?
忙于做某事为什么要用be busy doing sth 可以用be busy to do sth吗
be busy in doing sth
be busy doing sth 例句
英语大手解决困惑为什么be busy doing sth是doing呢那be afraid就是to do 有什么语法说下
是be busy doing sth还是be busy to do sth?
be busy doing sth/with sth
有什么英语词组像be busy doing sth ,反正就是be.doing sth的词组
为什么是be busy doing而不是be busy to do
be busy with sth 与be busy doing sth的区别 ,可以互换吗