+ =
﹣ =
1﹣ =
1﹣ ﹣ =
﹣0.125=
10+ =
+ ﹣ + =
=
打扫篮球场和教室的同学是全班的 .打扫阅览室的同学是全班同学的 .
+ = - = + = + =
- = × = × = - =
垃圾成分
可回收物
厨余垃圾
有害垃圾
其他垃圾
占总数的几分之几