在测电源电动势和内阻实验中,由于电源内阻较小,电压表示数变化不明显,作出的图像如

题型:实验题

问题:

在测电源电动势和内阻实验中,由于电源内阻较小,电压表示数变化不明显,作出的图像如图甲中A所示,这对数据处理的结果将引入较大误差,为了解决此问题,某同学在电路中串联了一定值电阻(如图乙),作出的图像如图甲中B所示,则此电源的电动势大小为         V,内阻为        

考点:实验:伏安法测电阻实验:练习使用示波器实验:测绘小灯泡的伏安特性曲线实验:探究影响导体电阻的因素
题型:实验题
设集合A={ x|x>2},a=
3
,则a ______A.
题型:实验题

急性前壁心肌梗死最常见的心律失常为()

A.室性过早搏动

B.房室传导阻滞

C.心房颤动

D.房性过早搏动

E.室上性心动过速

题型:实验题

先通读下面的短文,掌握其大意,然后根据短文内容和所给首字母,在空格内填入一个适当的词,使短文意思完整 。所填单词在题后横线上必须完整写出。

T he South China Sea Islands are m 小题1:  up of the East Sand Islands, West Sand Islands, Middle Sand Islands, South Sand Islands and Huangyan Island. A 小题2:  the islands of Nansha Islands, Huangyan Island is the only island above the China South Sea. It is r 小题3: in all kinds of fishes. It is one of the most beautiful t 小题4: attractions in China. Many people there still make a l 小题5:   by fishing from the sea. However, on April 10, 2012, the Philippine soldiers   b 小题6:   into this island. They threatened (威胁) our six fishermen by guns to stand in the sun for two hours without any clothes. They even r 小题7:  our fishermen to sign a file to announce that Huangyan Island belonged to Philippine, but was refused firmly.

“We will never give up! Huangyan Island has been part of China for c  小题8: ” a Chinese government official said a 小题9:  .With the help of the Chinese government, the six fishermen were saved at last and they succeeded in leaving the island s  小题10:   .They went back to China yesterday.

题型:实验题

头部外伤后出现双侧眼睑皮下淤血(熊猫眼征),提示()。

A.颅前窝骨折

B.颅中窝骨折

C.颅后窝骨折

D.以上都可能

E.以上都不是

题型:实验题

KU频段与C频段相比,一个明显的优点是雨衰较小。

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