如图是内燃机的某冲程工作示意图,以下取暖方式与此原理相同的是
A:烤火取暖
B:用热水袋取暖
C:向手“哈气”取暖
D:搓手取暖
方程x2=9的根是( )
It has two red eyes. What is it?
Be careful your things. Don't lose them.