下列物质中,只含有离子键,不含有共价键的是 [ ] A.HCl B.KOH C. 发布时间:2017-07-29 11:30 │ 来源:www.tikuol.com 题型:选择题 问题: 下列物质中,只含有离子键,不含有共价键的是 [ ]A.HCl B.KOH C.CaCl2 D.NH4NO3
题型:选择题 The first men to study the nature of electricity could not imagine that their experiments, carried on because of mere intellectual curiosity, would eventually lead to modern electrical technology, without which we can scarcely () contemporary life.A. get hold ofB. conceive ofC. get the better ofD. take advantage of 查看答案
题型:选择题 定义在R上的函数y=f(x)是增函数,且函数y=f(x-3)的图像关于(3,0)成中心对称,若s,t满足不等式f(s2-2s)≥-f(2t-t2),则1≤s≤4时,则3t+s的范围是 [ ]A、[-2,10] B、[4,16] C、[-2,16] D、[4,10] 查看答案