两个圆的周长相等，它们的面积[ ]
A．相等
B．不相等
C．无法确定
答案：A
The hospital _________ well, where many wounded ________every day.
A．is operated; operation
B．operates; are operated on
C．operates; are operated
D．operates; operates on
三室真空灌装机采用压差灌装原理，（）中的液体被压入包装容器。
A、上真空室
B、下真空室
C、真空室
D、储液箱
