斯塔夫里阿诺斯在《全球通史》中写道：“旧制度所显示的破产导致旧制度的变革。第一个变革是解放农奴……这是俄国历史上的一个重大转折点……工厂工人的数目从1865年的381000人上升到1890年的1620000人……”材料显示这次改革（    ）

正常人体中，下列数据不正确的是（   ）

阅读短文，下列问题

Computers are very important for the students now. For the city students, it's very easy to find a place to surf the Internet(网上冲浪). And for the village students, they can go to the Internet bar(网吧). Most of them spend more than two hours there, and some of them even spend more than eight hours there every day. They can do their homework, download(下载) some information for their homework, download music, send emails and play games.Most of them spend too much time playing games, so it's bad for their study.

在未知溶液中加入AgNO₃溶液有白色沉淀生成，加入稀硝酸后，沉淀部分溶解，有无色无味气体放出，将气体通入澄清石灰水变浑浊．则水溶液中含有（　　）