下列关于硫化氢或氢硫酸的描述,错误的是( )
A:硫化氢易溶于水,可做喷泉实验
B:硫化氢是一种弱酸,它具有酸的通性
C:硫化氢燃烧时,发出淡蓝色火焰
D:硫化氢受热易分解生成两种单质
本文读来虽显杂乱,但读后还是会给人留下比较深刻的印象,原因何在呢?
阅读。选择题,将正确答案的字母写在括号内。
I am Alice. We(我们) are in the playground(操场). We are playing football(踢足球). We are thirsty(口渴的). We are drinking. I like cola. Tom likes milk. Peter likes juice. Eddie likes water. We are happy.
使用动滑轮提升重物,能提高机械效率的做法是:( )