细菌和真菌在生物圈的物质循环中起着极为重要的作用，如图甲所示；这一原理也被用于解决生活污水造成的水污染问题．城市居民生活污水以其中的有机物为主，直接流入江河湖泊会使水质发黑发臭，污水处理厂将污水排入曝气池中，利用“活性污泥”（活性污泥是多种微生物聚合而成的泥絮状团块，其中最重要的是细菌）净化污水．图乙示某城市污水处理厂一角．请结合相关知识回答下列问题：

  80毫米和8分米一样长．____（判断对错）

假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文中共有10处语言错误，每句中最多有两处。每处错误仅涉及二个单词的增加、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：1.每处错误及其修改均仅限一词；

    Your problem is common one among middle school students. Maybe the following advices can help you. First in all, believe in yourself. Your greatest problem is that you lack(缺少) self-confidence. The first thing you must do is to smile at your classmate. One smile speaks loud about your wish to make friends than any word. Your smile will show that you are friendly to him. Next, trying talking with a student who is as shy as you or who share the same interest as you. You can discuss your studies with a classmate, and you can also talk about your hobbies as well. Unless anyone is in trouble, you should be ready to help him or her. Once you have confidence, you can make as many friends as possibly.