短文改错。便条中共有10处错误,每句中最多有两处。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（∧）。并在其下面写出修改后的词。
删除：把多余的词用斜线（＼）划掉。
修改：在错的词后划一横线,并在该词下面写出修改后的词。
注意：1）．每处错误及修改均仅限一词;
2）．只允许修改10处,多者（从第11处起）不记分。
    One day, I was cooking in the kitchen when the telephone rings. I went to answer it immediately. She was my close friend, Lisa. When we were talking on a phone, the fire alarm sounded. I dashed back to the kitchen. The room full of smoke and the beef was bad burnt. I quickly turned off the gas, opening all the windows, and then rushed out of the house. In my surprise, two fire engines were outside my house. I was rather worrying. I told about the firemen that it was my careless cooking which caused the heavy smoke.

如图，在Rt△ABC中，∠C=90°，BC=6cm，AC=8cm，按图中所示方法将△BCD沿BD折叠，使点C落在AB边的C′点，那么△ADC′的面积是（   ）

填适当的数． 

在平面直角坐标系中，点P的横坐标是－3，且点P到x轴的距离为5，则点P的坐标是（ ）

不能用来鉴别CO和CO₂两种气体的方法是(  )