the alien was buying a cap,i called my friend 用when还是while

the alien was buying a cap,i called my friend 用when还是while While the alien was buying a souvenir, the girl called the police中buy是延续性动词吗 同义句转换——英语八下While the alien was buying a souvenir,the girl called the police.While the alien was visiting the museum,the boy called the TV station.把句中的while改成when while the alien was buying a souvenir,the girl called the police.这个句子如果把while换成when可不可以?换了之后, 1.The girl called the police while the alien was buying a souvenir.(改为一般疑问句)________________________________________________________________2.The boy was doing his work when the UFO took off.(对画线部分提问）____________________ 1.The girl called the police while the alien was buying a souvenir.(改为一般疑问句)________________________________________________________________2.The boy was doing his work when the UFO took off.(对画线部分提问）____________________ 句型转换：1、The girl called the polic while the alien was buying a souvenir.改为一般疑问句 2、The boy was doing （his work）when the UFO took of.对括号部分提问 3、You can imagine how strange the alien was.改为感叹句 4、 1.while,took,we,down,were,off,walking,the UFO,the street2.was,called,buying,the police,a souvenir,the alien,when,the girl3.the alien,saw,the girl,shopping,get,when,out,she,was4.had,very,experience,Sunday,unusual,I,last,a5.the plane,raining,in,was,whe while the alien was buying a souvenir,the girl called the police.while不是只能跟持续性动词连用吗?buy不是短暂性动词吗?为什么这句话可以这样用呢? While the alien ____ a souvenir ,the girl called the police .A.was buying B bought为什么选A,如果换成是用when引导,这句话等于什么,请详解, while 后只能接延续性动词,那么为什么会有以下句子呢?while the alien was buying a souvenir,the girl called the policebuy不是非延续性动词吗?难道变成了进行时,就变成了一段时间吗? 翻译：I was watching TV when the alien landed . when she saw the alien为什么不加was 英语翻译1.My brother plays his CD too loud.2.What should i do?3.Why don't you talk to him about it?4.-What were you doing when the UFO arrived?-I was in the barber's chair.5.The barber was cutting my hair.6.While the alien was buying a souvenir,t 英语翻译1.While the alien __ a souvenir,the girl called the police.(A)A.was buying B.bought C.buys D.is buying2.When __the car__?Sorry,i do not know.（c）A.does,invent B.did,invent C.was,invent 3.Great changes __ in Tongren in the five years.(b The man was shopping when the alien got out 对was shopping 提问 时间状语从句时态（）the alien was buying a souvenir,the girl called the police.括号里为什么应该用while而不是when,从句用过去进行时,主句用一般过去时那What were you doing when the UFO arrived.这句话为什么反 关于状语从句 WHEN WHILE AS引导词的辨析While the alien was buying a souvenir,the girl called the police.ING谓语动词是不是延续性动词的标志?这时的While是否可以和when.as互换?是不是While引导时间较长,而as用