停用控制阀时候，必须先开副线，然后缓慢关闭上游阀的同时开大副线阀门，保持流量稳定。
参考答案：对
---What does you brother do?
---- .
A．He works very hard
B．He is outgoing and friendly
C．He is a shop assistant
D．He is tall with curly hair
下列哪一项不是卵巢非赘生性囊肿（）。
A.滤泡囊肿
B.皮样囊肿
C.黄体囊肿
D.黄素囊肿
E.多囊卵巢
