— John is under the weather today. He needs to see a doctor.
— I'm sorry to hear that.
A:hungry
B:tired
C:sick
4平方米=____平方分米
8平方米30平方分米=____平方分米
307平方厘米=____平方分米____平方厘米.
关于动物能够促进生态系统的物质循环的叙述,错误的是( )
一个几何体的三视图如图所示,则该几何体的体积为( )