气体灭火系统当采用火灾探测器报警时，应在接受到（）火灾信号后_爱下问搜题

搜题请搜索小程序“爱下问搜题”

问题单项选择题

气体灭火系统当采用火灾探测器报警时，应在接受到（）火灾信号后才能延时自动启动系统。

A.一个

B.两个

C.两个独立

D.三个

答案

参考答案：C

单项选择题

定影速度的正确表示是

A．定透时间
B．显影时间
C．定影时间
D．水洗时间
E．干燥时间

补全对话，情景问答

根据对话内容，从方框中选择适当的语句，使对话通顺、完整。

A. How long may I keep it?
B. You're welcome.
C. Can I help you?
D. Yon must return it on time.
E. What else can I do for you?

A: Good morning!
B: Morning! __1__.
A: I'd like to borrow the book David Copperfield. Have you got one?
B: Yes. Is it on the first shelf?
A: No, it isn't.
B: Let me look for it on the computer. Oh, It's on the third shelf.
A: Thanks a lot. __2__.
B: A month. __3_.
A: OK. Here's another book. I borrowed it a month ago. I have finished reading it.
B: All right. __4__.
A: Nothing else. Thank you very much.
B: __5_ Bey-bye.
1._____ 2._____ 3._____ 4._____ 5._____