为什么Michael当中一定要a,b-不饱和化合物才能与活泼氢反应原理谁能解释下少打2个字 是Michael加成

为什么Michael当中一定要a,b-不饱和化合物才能与活泼氢反应原理谁能解释下少打2个字 是Michael加成 轿车当中A.B. Who is that speaking?A.I am michael B.That is michael c.it is me d.This is michael michael didnt start__the importance of a foreign language untilhe graduated from school(to know)为什么不填know? A.Mrs B.Mr C.Mum当中与其他单词不同类的是那一个7 ( )13.Michael ____ swimming to ____ the sunshine on the beach.( )13.Michael ____ swimming to ____ the sunshine on the beach. A. prefered, enjoy B. preferred, enjoying C. prefered, enjoying D. preferred, enjoy 选什么,为什么 为什么(a^x)/lna在求导过程中,lna不求导,而在复合函数当中（x^2+3）当中3却要求导? i have a good friend————Michael from the USA.A calls B called C is called选哪个为什么 并说明选择原因Art is （ ） interesting subject.A .a B .the C .an D ./They play basketball （ ）two hours every day.A on B at C from D for为什么play在某些句子当中会加上ing形式,而在别的句式当中是play,加ing和不加in Michael used to look hurt and surprised when _.A.scolding B.having scolded C.to scold D.scolded请问为什么呢? Michael( )in beijing for3 years,he lives in New York at present.A.worked.B.has worked.为什么,还是答案错了 越狱中Michael为什么会死我看完了越狱,但是不知道Michael为什么会死,希望大家给个答案,谢谢~! How do you think ____ Michael will like China?这里为什么不填连词?而是/? Michael has been ill.Michael has ill.这个句子对吗?两句有什么区别?什么情况下要加been?为什么不能用has? 一种是拉A在木板B上匀速直线运动另一种是固定弹簧测力计,拉动木块B 此时不一定要匀速直线运动 为什么? 一种是拉A在木板B上匀速直线运动另一种是固定弹簧测力计,拉动木块B 此时不一定要匀速直线运动 为什么? ______has he been to beijing?A.How long B.How soon C.How many times D.How often为什么一定要选C 而不可以选A呢? [ ]is a good girl .A.Michael B.Colin C.Tina帮忙看看括号里应填什么