钢尺起始零点对不准、尺子读数不准、测钎插不准、线锤对点等引起的误差都属于()。A、丈 发布时间:2017-10-24 18:11 │ 来源:www.tikuol.com 题型:单项选择题 问题: 钢尺起始零点对不准、尺子读数不准、测钎插不准、线锤对点等引起的误差都属于()。A、丈量误差B、定线误差C、尺长误差D、拉力误差
题型:单项选择题 从方框内找出与所给句子应答的语句。 a. Sorry, I'm busy. b. It's often cool and windy. c. It's Tuesday. d. Let's find a restaurant nearby. e. The eighth. f. Thank you. g. Let's go and fly kites. h. Sure. I'll mop the floor. i. I'll close the window. j. In summer.( ) 1. Will you take a walk with me now ? ( ) 2. What day is today ? ( ) 3. Hi, Kate! You look very pretty today. ( ) 4. It's a lovely windy day. ( ) 5. It's so cold here in the room. ( ) 6. Can you help me with my housework ? ( ) 7. What's the weather like in autumn ? ( ) 8. Where shall we have our dinner, Dad ? ( ) 9. Which floor would you like to live on ? ( ) 10. When does school close ? 查看答案
题型:单项选择题 人们把黄昏的余晖与黎明的曙光相接的现象叫“白夜”。“白夜”出现时,虽然夜晚不见太阳,但天空仍是朦朦亮的,其主要原因是地球大气对太阳辐射的A.吸收作用B.散射作用C.逆辐射作用D.反射作用 查看答案
题型:单项选择题 如图所示,在x轴上方存在着垂直于纸面向里、磁感应强度为B的匀强磁场,一个不计重力的带电粒子从坐标原点O处以速度v进入磁场,粒子进人磁场时的速度方向垂直于磁场且与x轴正方向成120°角,若粒子穿过y轴正半轴后在磁场中到x轴的最大距离为a,则该粒子的比荷和所带电荷的正负是( )A.,正电荷B.,正电荷C.,负电荷D.,负电荷 查看答案