如图所示，理想变压器的原副线圈匝数比n1：n2=1：10，副线圈与阻值R=20Ω

发布时间：2017-07-08 17:06 │ 来源：www.tikuol.com

题型：多选题

问题：

如图所示，理想变压器的原副线圈匝数比n₁：n₂=1：10，副线圈与阻值R=20Ω的电阻相连．原线圈两端所加的电压u=20

sin20πt(V)，则（　　）

A．副线圈输出交流电的频率为10Hz

B．交流电压表的示数为20V

C．电阻R上消耗的电功率为2kW

D．原线圈中电流的最大值为100A

考点：变压器的结构和原理

题型：多选题

完形填空。

     On Saturday morning there are a lot of people in Xiqing Park. Jim and David  1 at the gate of the park.
They  2 to go into the park.
D: Wow! So many cars and  3  here! There must be many people in the park.  4  go in and have a look.
J: OK. Let's go.
D: 5  can we buy tickets? Where's the ticket office?
J: It's over there. Can you see the small window?
D: Yes, I see it.  6 is a ticket?
J: Look! It says two yuan for an adult (成年人), but one yuan  7  a school child.
D: Hmm, it's cheap. We are school children. So we can  8 two tickets for one yuan.
J: I'm afraid not (恐怕不行). We  9 have our school IDs.
D: Oh, that's right!
J: It doesn't matter (没关系). Let  10  go and buy two tickets for adults.

( )1. A. am
( )2. A .have
( )3. A. bus
( )4. A. Let
( )5. A Where
( )6. A .How
( )7. A. to
( )8. A. get
( )9. A. not have
( )10. A. I

B. is
B. want
B. buses
B. Lets
B. What
B. What
B. for
B. bring
B. doesn't have
B .me

C. are
C. wants
C. bike
C .Let's
C. How
C. How much
C. at
C. sell
C. don't have
C. my

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题型：多选题

某校九年级8位同学一分钟跳绳的次数排序后如下：150，164，168，168，172，176，183，185．则由这组数据得到的结论中错误的是（　　）

A．中位数为170

B．众位数为168

C．极差为35

D．平均数为170

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杀虫剂污染眼部后，可用下列哪种液体冲洗眼部（）

A.O.9%生理盐水

B.肥皂水

C.热水

D.高锰酸钾（1：5000）

E.2%碳酸氢钠

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题型：多选题

下面的语句用Array函数为数组a的各元素赋整数值：
a＝Array(1,2,3,4,5,6,7,8,9)
对数组变量a的正确定义是

A．Dim a

B．Dim a As Integer

C．Dim a(9) As Integer

D．Dim a() As IntegEr

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题型：多选题

当班用剩下的雷管炸药要（）。

A.放入箱中锁好，下班再用

B.直接交给下一班

C.出班时交回爆炸材料库

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