文中共有10处语言错误．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(^)，并在其下面写出谈加的词。
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：1．每处错误及其修改仅限一词。
2．只允许修改l0处，多者（从第11处起）不计分。
Now paper still come from trees. Unfortunately, we use a lot of paper every day. We mustn’t waste paper, or there will not have any trees leaving on the earth. No trees means no paper. We need 17 trees make one ton of paper. We must start using fewer paper. How can we save paper? Firstly, we can use both sides of paper. We can reuse again envelopes. We can use plastic cups and plates instead of paper one. We can either use handkerchiefs instead of paper tissues. Beside, we can use fewer paper shopping bags and we can reuse these paper bags late.
C(g)+D(g)，5 min后达平衡。已知该反应在此温度下平衡常数K＝1，若温度不变的情况下将容器的体积扩大为原来的10倍，A的转化率不发生变化，则B的转化率为