—When is his English Party?
—_____, I don't know. [ ]
A. Sorry
B. OK
C. Excuse me
D. Yes
A
我们通过对燃烧条件的探究,不难得出灭火的原因。请你判断以下灭火实例所依据的灭火原理是什么。
断4112P1泵填料泄漏情况的最好方法是观察底部排放水的情况。