请问while watching TV,we heard the doorbell ring.ring为什么不能加S啊?

请问while watching TV,we heard the doorbell ring.ring为什么不能加S啊? While she ---- newspapers,her mother was watching TV While I was watching TV,the phone______(ring) 填什么 When/While it began to rain ,I was watching TV He was watching TV while his wife was washing dishes. We enjoy watching TV.请问为什么watching要加ing while he came into the room,i was watching TV.改错 A.CAME INTO B.WATCHING TV 关于while的用法 Toby was watching TV while Tim____(do)his homework at 7 PM She entered the room ( )I was watching TV.请问括号里填when还是whilewhen和while都可以加do或者doing I FELL ASLEEP while watching tv.这句是不是完整的应该是：I FELL ASLEEP while I WAS watching tv.后面是过去进行时吧?I FELL ASLEEP while watching tv.为什么可以这么省略的写? 同义句转换：My sister fell asleep while she was watching TV last night.My sister fell asleep while she was watching TV last night.My sister fell asleep ( ) ( )was watching TV last night. 他在做作业时,我在看电视.While he ___ doing his homework,I ___ watching TV.他在做作业时,我在看电视.While he ___ doing his homework,I ___ watching TV.请问这里用现在进行时还是过去进行时?为什么? while my mother was cooking ,i ___ TV.A.was watching B.am watching C.watch D.watched Mr Zhou （）（fall）asleep while he was watching TV 动词填空... 整理下列句子 me/I/to/see/last night/came/watching/someone/while/was/TV We were watching TV ___ suddenly the light went out.填when还是 while?为什么? While she was reading,I was watching TV 对吗was reading My brother was watching TV when my mother came back（用while改写）