每隔()必须对甲烷超限断电闭锁和甲烷风电闭锁功能进行测试。
A、3天
B、6天
C、10天
D、15天
参考答案:C
Peter had lost his job, and the family was ________ a very difficult time.
A.going off
B.going through
C.going out
D.going down
缺乏何种激素时,能引起成人胰岛素敏感性增强和低血糖()。
A.生长激素
B.胰岛素
C.催乳素
D.促甲状腺激素
E.促肾上腺皮质激素