为什么是be busy doing而不是be busy to do

为什么是be busy doing而不是be busy to do be busy doing sth 为什么是动名词有神马规律吗 The students were busy doing their()when the teacher entered the classroomhomeworkshomeworklesson为什么是homework 而不是 homeworks呢? 语法请教What do you plan to be doing five years from now?为什么是to be doing 而不是done be busy doing造句 be+busy+doing=be+( )+( be busy doing 和 be busy in doing 的区别? be busy with doing 与be busy doing 区别 be busy doing等于什么 be busy doing sth 例句 be busy in doing sth be busy doing 过去式+造句 被动语态后接动词不定式为什么是be allowed to do sth 而不是be allowed doing英语中有allow to do 和doing两种么 为什么用be busy doing而不是be busy to do我觉得这个用法应该是be adj.to do 比如说be easy to do 为什么这个是be busy doing I prefer ( ) outside on sundays .为什么是 being 而不是to be?prefer to do 和prefer doing 不都行么 the man is skilled at repair the machine?为什么是 repair 而不是 repairing,不是be skilled at doing吗 She stood on the hill,her long hair streaming in the wind.这是英汉多功能的例句.那么这是什么时态?为什么是doing 而不是be doing? 句子翻译英文 我哥哥正忙着准备学校郊游 为啥是be busy with sth 而不是 be busy doing sth 呢