吸水管上应设过滤器，并应安装在（）。
A.压力表后
B.控制阀后
C.止回阀后
D.吸水管末端
参考答案：B
The famous athlete is from England.
A．comes to
B．goes to
C．comes from.
D．come from
The price of the bags is very __________.[ ]
A. dear
B. high
C. expensive
