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问题 多项选择题

无源光网络系统中双向传输技术是指上行信号和下行信号的传输复用技术，主括（）。

A.空分复用（SDM）

B.波分复用（WDMA）

C.副载波复用（SCM）

D.码分复用（CDM）

答案

参考答案：A, B, C, D

填空题

在横线上填入适当的单词或短语,补全对话。

A: What’s your trouble, Madam?

B: I feel very weak. I can hardly do any work.

A: How long have you been like this?

B: Ever   1  last month.

A: Have you got a headache?

B: No.

A: Do you usually   2  well at night?

B: Yes.

A: Do you often eat much?

B: No, I don’t often have breakfast. And I have a little food for lunch because I want

to   3  thin.

A: Oh, I see. There’s nothing   4  . You need to take much food and have three meals a day. And do some   5  every day. Then you’ll get better soon.
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单项选择题

项目团队想要获得LEED BD+C中高层住宅认证项目，应该满足哪个（）。

A.安装双冲马桶

B.安装高效节能节水器具

C.总体节水10%

D.浴室流量最大2.2GPM
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