在“青黏生于丰、沛、彭城及朝歌云”中,“云”之义为() A.说 B.地名 C.句末语 发布时间:2018-01-23 22:38 │ 来源:www.tikuol.com 题型:单项选择题 A1/A2型题 问题: 在“青黏生于丰、沛、彭城及朝歌云”中,“云”之义为()A.说B.地名C.句末语助词D.天空
题型:单项选择题 A1/A2型题 If people _____ the importance of living a low-carbon life earlier, there _____ so many environmentalproblems now. [ ]A. realized; wouldn't beB. had realized; wouldn't beC. had realized; wouldn't have beenD. realized; wouldn't have been 查看答案
题型:单项选择题 A1/A2型题 如图所示,两根光滑的金属导轨MN、M′N′平行固定于同一水平面内,导轨间距为l=0.50m,电阻不计.M、M′间接有阻值R=1.6Ω的电阻.金属棒ab垂直于导轨放置.导轨处于磁感应强度B=0.20T、方向竖直向下的匀强磁场中.金属棒ab在外力作用下向右匀速运动,速度v=10m/s,运动过程中金属棒ab与导轨保持良好接触.已知金属棒ab接入电路部分的阻值r=0.40Ω.求:(1)金属棒ab中电流I的大小和方向;(2)1min内电阻R上产生的热量Q. 查看答案