使用半自动闭塞法行车时，列车凭出站信号机显示的（）进入区间。_爱下问搜题

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问题单项选择题

使用半自动闭塞法行车时，列车凭出站信号机显示的（）进入区间。

A.出站信号

B.通过信号

C.进行信号

D.绿色信号

答案

参考答案：C

补全对话，情景问答

根据对话内容及方框中所给的句子补全对话。其中有两项是多余的。

A.I am so sorry to hear that.
B.Speaking of my mobile phone, it makes me annoyed.
C.How long have you had it?
D.Is the line clear?
E.The quality of the product is rather bad.
F.I an afraid so.
G.How often do you use it?

Teresa: Wow! Your mobile phone is really new.  1._______
Elise: For about two weeks.
Teresa: What brand is it?
Elise: It is Anycall.  There are many functions in it.
Teresa:2. _______
Elise: Yes, it's quite good.  ()h, Teresa, your mobile phone is very nice.
Tercsa:3. _______
Elise: What is the problem?
Teresa: I believed a misleading advertisement.  As a result, I bought it.  4._______
When I talk to other people on the mobile phone, the line is noisy.  I only send  messages.
Elise:  5._______You must never believe any advertisment that you don't know
well.  At times the picture in an ad looks a lot bett _______than the real thing.
Teresa: Yes, I think .so.

问答题

已知随机变量X的密度函数为

，求相应的分布函数F(x)。