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Part Four : Question : Which sentence below is a comment rather than a statement of fact? Radioactive 6 Marie next decided to test all of the known chemical ores to see if any others would emit Becquerel rays. In 1898, she coined the term “radioactive” to describe materials that had this effect. Pierre was so interested in her research that he put his own work aside to help her. Together, they found that two ores, chalcolite and pitchblende, were much more radioactive than pure uranium. Marie suspected that these ores might contain as yet undiscovered radioactive elements. 7 Several tons of pitchblende were donated by the Austrian government, but the space Marie was using for a lab was too small. The Curies moved their research to an old shed outside of the school. Processing the ore was backbreaking work. New protocols for separating the pitchblende into its chemical components had to be devised. Marie often worked late into the night stirring huge cauldrons with an iron rod nearly as tall as her. 8 Little by little, various components of the ore were tested. The Curies found that two of the chemical components, one containing mostly bismuth and another containing mostly barium, were strongly radioactive. In July 1898, the Curies published their conclusion: the bismuth compound contained a previously undiscovered radioactive element that they named polonium, after Marie’s native country, Poland. By the end of that year they had isolated a second radioactive element they called radium, from radius , the Latin word for rays. In 1902, they announced success in extracting purified radium. 9 In June 1903, Marie was the first woman in Europe to earn a doctorate in physics. In November of that year the Curies, together with Henri Becquerel, were named winners of the Nobel Prize in Physics for their contributions to the understanding of atomic structure. The nominating committee objected to including a woman as a Nobel Laureate, but Pierre insisted that the original research was Marie’s. In 1911, after Pierre’s death, Marie was awarded a second Nobel Prize in Chemistry for her discovery of the elements polonium and radium.
A.
Marie next decided to test all of the known chemical ores to see if any others would emit Becquerel rays.
B.
Processing the ore was backbreaking work.
C.
In 1902, they announced success in extracting purified radium.
D.
The nominating committee objected to including a woman as a Nobel Laureate, but Pierre insisted that the original research was Marie’s.
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【多选题】以下是网站规划可行性分析的是
A.
经济可行性
B.
技术可行性
C.
实施可行性
D.
信仰可行性
【多选题】电气控制原理图一般分为()和()两部分。
A.
主电路
B.
控制电路
C.
辅助电路
D.
照明电路
【单选题】病人,男,65岁,高血压史20年,晚餐时突然剧烈头痛伴呕吐,并迅速昏迷。体检:血压为220/140mmHg,首先考虑
A.
脑血栓形成
B.
蛛网膜下隙出血
C.
脑膜炎
D.
腔隙性脑梗死
E.
脑出血
【单选题】图中所示电阻的阻值为()KΩ
A.
6.52
B.
65.2
C.
652
D.
6520
【简答题】欲使图(a)所示电路中2Ω电阻的功率为4Ω电阻功率的两倍,求电压源电压E值的大小。
【简答题】测得一辆在用的气压制动汽车前轴质量为1050kg(左右轮各占一半),后轴质量为1200kg(左右轮各占一半)。测出其前轴制动力最大值分别为:左轮3400N,右轮3000N,车轮阻滞力分别为150N和200N,在制动力增长全过程中同时测得的左右轮制动力差的最大值为160N。后轴制动力分别为3800N和3200N。车轮阻滞力分别为130N和150N,在制动力增长全过程中同时测得的左右轮制动力差的最大值...
【单选题】如图所示电路,电源电压6 V保持不变,定值电阻的阻值 为10 Ω,滑动变阻器的最大阻值为20Ω,当开关闭合, 滑片由b端向a端移动的过程中,以下说法正确的是
A.
当滑片移到a端时,电流表示数为0.2 A
B.
当滑片移到中点时,电压表示数为2 V
C.
电压表示数与电流表示数的比值不变
D.
电压表的示数减少
【简答题】用如图甲所示电路可以测量一个未知电阻的阻值,其中 Rx 为待测电阻,R 为电阻箱, S 为单刀双掷开关,R0 为定值电阻.按照正确操作步骤,调节好电阻箱,其示数如图乙所 示,则它的示数为____ Ω.若已知 R0 的阻值为 1OΩ,则待测电阻 Rx 的阻值为____ Ω.
【单选题】如图2-10所示电路中,电阻R的阻值为( )Ω
A.
1
B.
5
C.
7
D.
6
【多选题】以下是网站规划书内容的是?
A.
项目概述
B.
需求分析
C.
可行性分析
D.
项目预算
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