什么是绝热过程举例说明。
参考答案:气体在状态变化过程中与外界无热量交换。在绝对过程中,系统靠消耗自身内能对外做功。如空气压缩机压缩空气,高速气流流过阀口等为绝对过程。
北京天坛公园的祈年殿是个底部直径约32.7米的圆形大殿。它的占地面积大约是多少平方米?回音壁是一道圆形的水磨砖围墙,它内圆的半径是30.8米。回音壁内圆的周长大约是多少米?
Twenty people were killed in the bus disaster, the bus driver himself.
A.containing
B.included
C.including
D.contained