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【简答题】
The word horsepower(马力)was first used two hundred years ago. James Watt had made the first widely used steam(蒸气)engine. He had no way of tellingpeople exactly how powerful it was, for at that time there were no units for measuring(测量) power. Watt decided to find out how much measure the work his steam engine could do. He discovered that a horse could lift a 3,300-pound weight 10 feet into the air in one minute. His engine could lift a 3,300-pound weight 100 feet in one minute. Because his engine did ten times as much work as the horse, Watt called it a ten horsepower engine. 1、The passagesays that Watt made the first widely used steam engine. 2、Watt made up a unit of measurement based on the strength of a horse. 3、Watt wanted to find a way to lift a 3300-pound weight. 4、One horsepower would equal the weight a horse could lift. 5、The title of the passageis 'How the Term Horsepower Came into Being'.
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【多选题】为了便于在文档中查找信息,可以使用_____符号来代表任何一个或多个字符进行匹配。(多选)
A.
&
B.
%
C.
D.
*
【简答题】设放大倍数为A反馈系数为F正弦波振荡电路产生自激振荡的平衡条件是 ____。
【单选题】血液中使呼吸运动加强的主要因素是
A.
二氧化碳分压升高
B.
氧气分压降低
C.
乳酸增多
D.
非蛋白氮增多
【单选题】WORD中为了便于在文档中查找信息,可以使用( )符号来代表任何一个字符进行匹配。
A.
*
B.
&
C.
%
D.
?
【判断题】为了便于在文档中查找信息,可以使用?符号来代表任何多个字符进行匹配。
A.
正确
B.
错误
【判断题】初中地理教学媒体选择主要是为了揭示地理事物的内在规律和原理。
A.
正确
B.
错误
【判断题】为了便于在文档中查找信息,可以使用?符号来代表任何多个字符进行匹配
A.
正确
B.
错误
【单选题】鸽子走路的时候用什么方式来保持平衡?
A.
挥动双翅
B.
晃动身体
C.
把头探来探去
D.
摆动尾巴
【多选题】如图 所示是 RC 正弦波振荡电路,下列说法正确的是 ( )
A.
电路在起振阶段,要求:
B.
振荡稳定后,要求电路的放大倍数等于3
C.
设电路中两个电容都为C,则振荡角频率为:ω=1/RC;
D.
设电路中两个电容都为C,则振荡频率为:f=1/(2πRC);
E.
若反馈电阻为热敏电阻,应该使用正温度系数的热敏电阻。
F.
若R1为热敏电阻,应该使用正温度系数的热敏电阻。
【单选题】患者,女性,29岁,主诉恶心呕吐,月经延迟2周。为明确诊断,医嘱做尿妊娠试验检查。护士让患者留取晨尿检验的目的是( )
A.
尿中尿素、尿酸浓度高
B.
不受饮食的影响尿中尿素、尿酸浓度高
C.
尿中磷酸盐浓度高
D.
尿中绒毛膜促性腺激素含量高
E.
尿中酸碱度未改变
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