问题
选择题
下列有关水的叙述正确的是 [ ]
A.水是一种非电解质
B.纯水中c(H+)随着温度的升高而降低
C.由液态水结成冰的过程是一个熵增的过程
D.25℃,pH相同的氢氧化钠溶液与醋酸钠溶液,水的电离度前者小于后者
答案
答案:D
下列有关水的叙述正确的是 [ ]
A.水是一种非电解质
B.纯水中c(H+)随着温度的升高而降低
C.由液态水结成冰的过程是一个熵增的过程
D.25℃,pH相同的氢氧化钠溶液与醋酸钠溶液,水的电离度前者小于后者
答案:D
We have no idea about 1 men first began to use salt. But we do know that it had been used in many different ways __2___ the history. For example, in many history books it is __3__ that people who lived three thousand years ago __4__salted fish. Thousands of years ago in Egypt(埃及), salt __5_ keep the dead. It can keep the dead bodies __6__ decay.(腐烂) In the eighteenth century, a person who stole salt was __7__ to have broken the __8__. if a person was caught stealing salt, he would be thrown into __9__. Books also record that in England about ten thousand people were put into prison during that century _10__ stealing salt! In the year 1553, if a man took __11__ than his share of salt, he would be thought to have broken the law and would be __12__ punished(惩罚). Salt was very __13__ on the dinner table of a king. It was always put __14__ the king when he sat down to eat. Then important visitors sat near the salt __15_ less important visitors were given seats farther away from it.
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