若21-i=a+bi(a，b∈R)（i为虚数单位），则a+b=______．

发布时间：2017-05-19 20:32 │ 来源：www.tikuol.com

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问题：

若

2

1-i

=a+bi(a，b∈R)（i为虚数单位），则a+b=______．

考点：复数的概念及几何意义复数相等的充要条件

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大华同学用伏安法测灯泡的数据如表．请根据表中的数据，完成下列问题：

实验次数	电压表示数（伏）	电流表示数（安）
1
2	2.0	0.20
3	2.5	0.26

（1）在图中，将实物图连接完整．

（2）大华同学第1次测量时电流表、电压表的示数如图所示，请将数据填入表相应的位置．

（3）从第2次测量到第3次测量时，应将滑动变阻器的滑片P向______移动．

（4）待测灯泡电阻的平均值是______．（精确到小数点后一位）

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关于S₂分裂，错误的是（）

A.生理性分裂在青少年更常见

B.二尖瓣狭窄伴肺动脉高压可通常有分裂

C.固定分裂可见于先天性心脏病房间隔缺损

D.反常分裂可见于完全性右束支传导阻滞

E.主动脉瓣狭窄可出现逆分裂

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A passenger told an air hostess that he needed a cup of water to take his medicine when the plane just took off. She told him that she would 21 the water in ten minutes.
Thirty minutes later, when the passenger’s ring for 22 sounded, the air hostess realized it at once. She was kept so 23 that she forget to deliver him the 24 . As a result, the passenger was 25 to take his medicine. She hurried over to him 26 a cup of water, but to her surprise he 27 it.
In the following hours on the 28 , each time the air hostess passed by the 29 , she would ask him with a 30 whether he needed help or not. But the passenger 31 paid attention to her words.
When he was going to get 32 the plane, the passenger asked the air hostess to 33 him the passenger’s booklet(意见簿). She was very 34 . She knew that he would write down 35 words, which might result in the loss of her job. 36 with a smile she handed it to him.
Off the plane, she 37 the booklet and cracked a smile, 38 the passenger put it, “On the flight, you asked me whether I needed help or not for twelve times 39 . How can I refuse your twelve sincere smiles?”
That’s 40 ! Who can refuse twelve sincere smiles from a person?

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水中的溶解物越多，一般所含的盐类也越多。

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温病多部位多窍道出血时怎样选择止血药？

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