各举一个be+doing+while+be+doing和be+doing+when+did的例句,be最好为过去时

各举一个be+doing+while+be+doing和be+doing+when+did的例句,be最好为过去时 be gifted at doing举两个例子 () i am writing this ,you can be doing something elseA.while B.when C.as D.for be accustom to do(不是doing!请举例句, need doing =need to be举个列子 正在进行时be+doing怎么加 最好举上例子 while he will be doing his homework,i will be playing basketball.改错 finish to do 与finish doing有什么不同最好各举一个例子 I( ) some shopping with my mother （ ) I ran into Linda.A.did,while B.did,when C.was doing,while D.was doing,while 为什么选B,D为什么不正确啊,买东西不是一个过程吗?选项有误D.was doing,when ____ his homework,there was a call for him.A While doing B When doing C Doing D While he was doing我是一个学生,分析一下错误的答案为什么会错!我现在无法立即选择答案,我很有很多问题输入,一会全输完了我会一 while doing 是一种省略主语+be的用法 那有没有when doing这种省略?请问 be doing与be to do的区别希望举些例句来说明 while做“当.的时候”时后面一定是be+doing吗?人称在前而“while”后没有人称时是不是只加doing呢? while walking in the street ,you have to be very careful toavoid__down by passing cars or trucks.a.to be knocked b.being knocked 答案为什么不是a?不应该是将来吗?虽然avoid+doing,可是前面还有while while 的主句不是要+done吗? be+doing be kind 可以举一个例子吗? what were you doing __your father__back?A.while ;came B.when ;came C.while ;was coming D.when ;was coming Will+be+doing是什么时态举个例子好吗 最好勉强翻译下`````````````