水文特征和水系特征

既能显示酸性又能发生加成反应的是（）A CH3COOH B CH2=CH-COOHCH3COOH为什么不能发生加成反应?乙酸中不是存在C=O吗？这个C原子也应该是不饱和的啊！为什么不会发生加成反应？ 同性恋是如何形成的 Where shall we put the table,Mrs.li?保持原句意思Where ____________ ________________ __________the table,Mrs.li? Where shall i put the bottle? What is it like?It's ____ .A.a new B.new C.windy 最好加上原因, Where do you the round table ,Mrs Li? where should we put the chairs? where shall we put the tick?怎么翻译这句话? what is your new bag__?(like likes look like) 填什么 酯化反应在浓硫酸催化作用下可逆吗?浓硫酸不是吸水吗?这样的话,你反应就不能进行了啊? 用2,3,8,12四个数凑24同上, 2,-4,12,1四个数用加减陈除得24,注每个数用1次, 煞风景里的“煞”读一声还是四声? There are more than fifty proposals ________ at the conference.A) discussedB) to be discussedC) discussingD) having been discussed 登陆南极的第一人到底是谁啊!急!是阿蒙森还是莫斯特呀! 登陆南极的第一人到底是谁啊!阿蒙森还是莫斯特? what did the writer give him in return for this?是谁报答谁?新概念英语book2,lesson6 what did the writer give him in return for money what did the writer give him in return for money the writer did give him for a meal and a glass of beer in return for money .这个回答对吗? 英语翻译【在摘要写作里的,不要合成一个段落!】急.回答要完整,不要乱凑数,不然是不会得到“最佳答案”和10积分的.还有，先回答，再给10积分！说到做到！绝对守信用！ What did the write give hin in return for him 要很准!What did the writer give him in return for this 化学元素Tc为什么是放射性?它下面的都不是啊?白金有是什么元素组成的? 1.If my brother __________ come,give him this letter.A.would B.should C.will have D.ought这一题选什么呢?可是想问问为什么不选A 花田半亩那部书中的田维得的类似血癌的病是什么病? 已所不欲勿失于人已所欲失于人 请给我举几个“已所不欲,勿失于人”的例子, 铂金溶于水银吗?或者说铂族金属溶于水银吗?有相关文献记载吗?听说黄金溶于水银,难道铂金比黄金更稳定?怎样能分离开黄金、铂金、镍铁,这三样的合金? 已所不欲,勿加于人是什么意思_ Gay形成的原因? gay的形成是怎样的,与什么有关? GAY是怎么形成的/天生的? gay是怎样形成的 您好?我想问的是,写氯化钠的化学式时为什么只选氯元素的负一价?氯元素有几个化合价呀!