压缩机发生液击时，应关闭吸气截止阀主通道，严重时应立即（）。
A.增大
B.不变
C.减少
D.不清楚
参考答案：B
Learning English means _________ memorizing a huge lot of words．It involves a large amount of reading as well．
A．other than
B．more than
C．rather than
D．less than
下列属于抑菌剂的抗菌药为（）
A.磺胺类
B.大环内酯类
C.氯霉素类
D.四环素类
E.氨基糖苷类
