题目

每句中只有一个错误。每处错误涉及一个单词的增加、删除或修改。增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。删除：把多余的词用斜线（＼）划掉。修改：在错的词下划一横线，并在该词下面写出修改后的词。注意：每处错误及其修改均仅限一词。 Water is very important to us, without that there would be no life. therefore, some people don't turn the tap off at once after using it. some people don't realize they wash them in the shower too long. Some even threw away bottles full下列化学符号错误的是A．氯化镁：mgcl2B．氦气：HeC．3个亚铁离子：3Fe2+D．2个氮原子：2N