两个距离较近的二电平FSK信号发射机,一个在150MHz频段,另一个在280MHz频

题型:单项选择题

问题:

两个距离较近的二电平FSK信号发射机,一个在150MHz频段,另一个在280MHz频段,如果它们产生了二阶互调产物,则该产物在频谱仪上显示有()个峰。

A.1

B.2

C.3

D.4

考点:无线电监测技术无线电监测技术题库
题型:单项选择题

Hi,I’m Mimi. I’m four years old. I enjoy listening to music very much. I can sing and dance. This is a photo of me at my birthday party. I look very cool because it is my birthday today.It is favorite day of this year.I get up early and I’m ready for my birthday party.I have a lot of animal friends .iIcall them to my home on the phone. Then I take a bus to go shopping. I buy some food ,friut and drinks in the super market.At 7:0p.m,the party begins.All my friend asks me to sing some songs for them .I’m shy in front of them but I feel happy.Look! I’m playing guitar.They are listening tomy songs They clap their hands from time to time.at last ,all my friends walk to me and sing.” Happy birthday” to me.How happy my birthday is !And my friends have a good time .

小题1:How old is MiMi?

A.2

B.4.

C.14.

D.40小题2:.Why does MiMi look cool today?Because____________

A.his animal friends come.

B.his parents love him.

C.it is his birthday.

D.he wears nice clothes.小题3:How does he go shopping?

A.By bus

B.By taxi

C.By train

D.By bike小题4:What time does the birthday party begin?

A.5:00 a.m

B.6:30 p.m

C.7:00 a.m

D.7:00p.m小题5:Which is Not true?

A.MiMi buys food ,fruit and drinks.

B.MiMi can’t sing and dance.

C.MiMi feels shy in front of his friends.

D.Friends sing“Happy birthday”to him .

题型:单项选择题

根据《水电站基本建设工程验收规程》(DL/T5123--2000)的规定,中型水电站的竣工验收应由()负责。

A.项目法人

B.地方政府

C.项目审批部门

D.国家能源局

题型:单项选择题

中间站调车

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下列操作中,无法打开Windows资源管理器窗口的是( )。

A.用鼠标右健单击桌面上的“我的电脑”图标,在弹出的快捷菜单中选择“资源管理器”命令

B.用鼠标右键单击“开始”按钮9在弹出的快捷菜单中选择“资源管理器"命令

C.用鼠标右健单击桌面上的“回收站”图标,在弹出的快捷菜单中选择“资源管理器”命令

D.用鼠标右键单击“任务栏”的空白处,在弹出的快捷菜单中选择“资源管理器”命令

题型:单项选择题

常用的联网型出入口控制设备有单门、双门、四门控制器等。

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