一个意志坚强的人,能在复杂的情景中冷静而迅速地判断发生的情况,毫不迟疑地采取坚决 发布时间:2017-04-30 05:59 │ 来源:www.tikuol.com 题型:选择题 问题: 一个意志坚强的人,能在复杂的情景中冷静而迅速地判断发生的情况,毫不迟疑地采取坚决的措施和行为,这种表现是[ ]A.自觉性 B.果断性 C.坚韧性 D.自制力
题型:选择题 “加速度计”作为测定物体加速度的仪器,已被广泛地应用于飞机、潜艇、导弹、航天器等装置的制导中,如图44所示是“应变式加速度计”的原理图.支架A、B固定在待测系统上,滑块穿在A、B间的水平光滑杆上,并用轻弹簧固接于支架A上,其下端的滑动臂可在滑动变阻器上自由滑动.随着系统沿水平方向做变速运动,滑块相对于支架发生位移,并通过电路转换为电信号从1、2两接线柱输出.已知滑块质量为m,弹簧劲度系数为k,电源电动势为E,内电阻为r,滑动变阻器总阻值R=4r,有效总长度为L.当待测系统静止时,滑动臂P位于滑动变阻器的中点,且1、2两接线柱输出的电压U0=0.4E.取AB方向为参考正方向.(1)写出待测系统沿AB方向做变速运动的加速度a与1、2两接线柱间的输出电压U间的关系式.(2)确定该“加速度计”的测量范围. 查看答案
题型:选择题 情景对话,选择最佳答案补全对话。Black is a teacher. He has a headache and goes to see a doctor. (B: Black ; D: doctor) D: Come in. Please sit down. B: Thank you, doctor. D: 1. B: Doctor, I have a headache …..a bad headache. D: I see. 2. B: I'm a teacher. D: A teacher ….um…..Do you smoke? B: Yes, I do. About fifteen cigarettes a day. D: 3. I mean, do you take any exercise? Do you play tennis? Do you swim? B: No, I don't have the time. 4. D: Now listen, please. You've got two problems, 5. . Neither of them is good for your health. You'd better stop smoking and take more exercise if you want to keep healthy. A. How can I help you B. You smoke and you don't take exercise. C. What's your trouble? D. And what about exercise?E. By the way, what do you do? F. I work hard and I have a lot of things to do. G. Where do you work? 查看答案