某兴趣小组为了测定一遥控电动小车的额定功率，进行了如下实验：

搜题请搜索小程序“爱下问搜题”

问题实验题

a．已用天平测出电动小车的质量为0.40 kg；

b．将电动小车、纸带和打点计时器按如图甲所示安装；

c．接通打点计时器（其打点时间间隔为0.02 s）；

d．使电动小车以额定功率加速运动，达到最大速度一段时间后关闭小车电源，待小车静止时再关闭打点计时器电源（设小车在整个过程中所受的阻力恒定）。

在上述过程中，打点计时器在纸带上所打的部分点迹如图乙所示，请分析纸带数据，回答下列问题（保留2位有效数字）：

(1)该电动小车运动的最大速度为____m/s；

(2)该电动小车的额定功率为____W。

答案

（1）1.5

（2）1.2

单项选择题

Fear seems to be the dominant mood of the moment. Hurricanes, tidal waves, floods, earthquakes and terrorism this year have all brought with them not only appalling scenes of devastation, death and suffering, but also outrage at the lack of preparations to avoid or cope with these disasters. Now even the birds of the air are a threat, we are told. That migrating flock visible On the horizon at sunset, once a consoling reminder of the eternal rhythms of nature, could be carrying the virus which might soon kill tens of millions of people.

Given the many fingers pointed at governments in the wake of other disasters this year, it is hardly surprising that they are scrambling to respond to the threat posed by avian influenza. After confirmation this week that the HSN1 strain of bird flu, which has been spreading quickly in Asia, had been discovered in Romania and perhaps Greece, European Union foreign ministers convened an emergency meeting. President George Bush, still smarting from a torrent of criticism of his government’s clumsy response to Hurricane Katrina, has promised to rush out emergency plans for dealing with an outbreak of pandemic flu which have been stalled for years. Countries around the world are hurrying to stockpile the only current antiviral drug, Tamifln, which might be effective in saving lives in any pandemic or curbing its spread. The World Health Organisation is calling for an internationally coordinated effort. Health ministers from around the globe are due to meet next week in Canada to discuss what steps to take.

Is any of this eff6rt justified Or are politicians simply helping to feed public panic, and then covering themselves by promising to spend lavishly against a threat which may never materialize and to reduce a risk which they do not understand To ask these questions is not to counsel complacency, but to apply the kind of test which is required in any kind of disaster planning, not least because the world is an inherently dangerous place and it is impossible to plan against every possible disaster. With the media full of warnings of impending mass death, an overreaction is all too possible.

The phrase "not least" in the last but one sentence of the text means （）

A. at most

B. not at all

C. marginally

D.particularly

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单项选择题

下列存货发出计价方法中，存货成本流转和实物流转相一致的方法是（）。

A.移动平均法

B.先进先出法

C.个别认定法

D.毛利率法

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