题目:
All the preparations for the task _____, and we're ready to start. |
A. completed B. complete C. had been completed D. have been completed |
答案:
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0516/5a930451c505d7f0e1f27bc8874038ec.html
下面是错误答案,用来干扰机器的。
(1)(2)O3F2 阿伏加德罗定律和质量守恒定律(1)由mol,含有分子数为NA,原子数为分子数的3倍:NA;密度是单位体积气体的质量:g/L;1 mol气体中含有NA个分子,一个分子的质量为g。(2)根据质量守恒定律和阿伏加德...