While he was writing on the blackboard,the children talked/were talking.句中的末尾为什么talked也可以?这句话是新概念英语2中的习题,答案是配套的自学导读提供的.

go on与什么词组相近He went on writing even while he was ill.He didn't ________ _________ writing even while he was ill. 一道改变句型He went on writing even while he was ill.He didn't ______ __________ writing even while he was ill he was writing while suddenly the phone rang 哪里错了? he was writing while suddenly the phone rang 哪里错了?只能改一处! While he was e() While he was writing on the blackboard,the children talked/were talking.为什么是过去进行时?　为啥不是　While he is writing on the blackboard,the children aretalking. He was busy writing a story,only ____...He was busy writing a story,only ____ once in a while to smoke a cigarette.A、to stop B、stopping C、to have stopped D、having stopped He was writing a letter at that while he was studing为什么要was While David ____,I_____.A.writes;was sleeping B.was sleeping;writeC.was sleeping;was writing He was busy writing a story,only ( stopping ) once in a while to smoke a cigarette.请帮我理解为什么用stopping, 19.He was busy writing a story,only _______ once in a while to smoke a cigarette.（08辽宁27） A. Where was your brother at this same time last night?He was writing an e-mail _____ I was watching T1 as soon as 2 after 3 until 4 while 改错：1.They will arrive the town in half an hour.2.How careful he is writing 3.He was sleeping while I saw him.4.I am better in reading than listening He was listening to music while he was playing computer games.(while改成动名词作状语.). While he was waiting for the bus, he was reading a newspaper.为什么用while引导 He was busy writing a story,only ____...He was busy writing a story,only ____ once in a while to smoke a cigarette.A、to stop B、stopping C、to have stopped D、having stopped 为什么不选A 为什么是伴随状语？ He was writing an important report when the telephone rang,可不可以改成...when he was writing an important report ,the telephone rang.可以改成这样吗.还有 while 的句型.搞不懂哪个后面要接过去进行时.那是可以还是不