公安消防支队应当按照防护装备技术状态简易判定标准,()组织对所属部队防护装备进行质量性能抽检,并将抽检情况向总队报告。
A.每半年
B.每年
C.每月
D.每周
参考答案:A
(1)在 "探究小车速度随时间变化规律" 的实验中,下列说法正确的是
A.电火花计时器正常工作时,其打点的周期取决于交流电压的高低
B.电火花计时器应接在10V以下的交流电源上才能正常工作
C.打点计时器连续工作时间很短,应注意打点之后要立即关闭电源
D.开始实验时,应先接通电源,后释放小车(2)某同学在实验中,由打点计时器得到表示小车运动过程的一条清晰纸带如图所示,纸带上两相邻计数点的时间间隔为T=0.10s,其中S1=7.05cm、S2="7.68" cm、S3="8.33" cm、S4="8.95" cm、S5="9.61" cm、S6="10.26" cm,则D点处瞬时速度大小是 m/s,计算小车运动加速度的表达式为 ,加速度大小是 m/s2(计算结果保留两位有效数字)。
(3)另一同学利用气垫导轨测定滑块的加速度,滑块上安装了宽度为3.0 cm的遮光板,如图所示,滑块在牵引力作用下先后匀加速通过两个光电门,配套的数字毫秒计记录了遮光板通过第一个光电门的时间为Δt1=0.30 s,通过第二个光电门的时间为Δt2=0.10 s,遮光板从开始遮住第一个光电门到开始遮住第二个光电门的时间为Δt=4.0 s.试估算:滑块经过第一个光电门时的速度大小v1=____________ m/s;在下滑过程中,滑块的加速度大小a=____________ m/s2。
Aristotle was one of those who could found a civilization, and while he thought of education as both a social value and an end in itself, he ascribed its chief importance (21) what might be considered a third basic concept of education: to train the mind to think, (22) what it is thinking about. The key is not (23) it knows but how it (24) any new fact or argument. "An educated man," Aristotle wrote in On the Parts of Animals, "should be able to (25) a fair offhand judgment as to the goodness or badness of the method used by a professor in his exposition. To be (26) is in fact to be able to do this." The Aristotle view of education as a (27) has become the conventionally worthy answer today (28) college presidents and other academic leaders are asked what an education should be. An educated man, says Harvard President Bok, (29) a deep breath, must have a "curiosity in (30) the unfamiliar and unexpected, an open-mindedness in entertaining opposing points of view, (31) for the ambiguity that surrounds so many important issues, and a willingness to make the best decision he can in the fact of uncertainty and doubt." This is an approach that appears to (32) more importance to the process of learning (33) to the substance of what is learned. The very old notion of the generalist who could comprehend all subjects has (34) been an impossibility. To make matters (35) more difficult, the fields of knowledge keep changing.
A. tolerance B. intolerance C. coordination D. indulgence