下面短文中有10处语言错误，请在有错误的地方增加、删除或修改某个单词。

增加：在缺词处加一个漏词符号（∧），并在其下面写上该加的词。

删除：把多余的词用斜线(＼)划掉。

修改：在错的词下划一横线，并在该词下面写上修改后的词。

注意

1．每处错误及其修改均仅限一词；

2．只允许修改10处，多者（从第11处起）不计分。

Over the past twenty years or so, great changes have been taken place in our life.Taking my family for example. My parents keep in touch with others mainly by sending letters in the past. And now we make long-distance calls at home, Once my parents listened  the radio for news and other informations. But now we get to know about the world .by watching TV or surfing the Internet. There is another big change. When my parents got marry about twenty years ago, they lived in a small room crowding with furniture. But now we have moved into a big new three-room apartment. On short, our life has become more comfortably and convenient.

在手控调节给水量时，给水量为何不宜猛增或猛减？