试题与答案

室内定向板状天线采用(),要求天线周围无直接遮挡物,天线主瓣方向正对目标覆盖区。A.

题型:多项选择题

题目:

室内定向板状天线采用(),要求天线周围无直接遮挡物,天线主瓣方向正对目标覆盖区。

A.吸顶安装方式

B.壁挂安装方式

C.悬空安装方式

D.利用定向天线支架安装方式

答案:

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参考答案:由于离子交换树脂对于水中各种离子吸着(或吸附)的能力不相同,对于其中一些离子很容易被吸着,而对另一些离子却很难吸着。被树脂吸着的离子,在再生的时候,有的离子很容被置换下来,而有的却很难被...

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题型:单项选择题

Passage Two

One hot night last July,when our new baby wouldn’t or couhln’t sleep, I tried everything I could think of:a warm bottle, songs, gentle rocking. Nothing would settle him. Guessing that I had a long night ahead of me, I brought a portable TV into his room,figuring that watching the late movie was as good a way as any to kill of the hours till dawn. To my surprise, as soon as the TV lit up, the baby quieted right down, his little eyes focused brightly on the tube. Not to waste an opportunity for sleep, I then tiptoes out of the room,leaving him to watch the actors celebrate John Bellushi’s forty-fifth birthday.

My wife and I heard none of the baby that night, and the next morning when I went into his room, I found him still watching TV himself.

I found in my baby’s behavior a symbol of the new generation. My wife and I had given him some books to examine, but he merely spit upon them. When we read to him, he did not feel comfortable. And so it is in the schools. We find that our students don’t read and they look down upon reading and scold those of us who teach it. All they want to do is watch TV. After this experience with the baby, however, I have reached a conclusion : "Let them watch it ! "If television is that much more attractive to children than books,why should we fight about it Let them watch it all they want!

From this passage we know that the author is().

A.a doctor

B.a reporter

C.an editor

D.a teacher

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