题目: 3A的直流电通过电阻R时,t时间内产生的热量为Q;现让一交流电通过电阻R,若2t时间内产生的热量为Q,则该交流电流的有效值和最大值分别为( )A.I有=3/2A,Im=3AB.I有=3A,I有=3AC.I有= A,I有 AD.I有3A,Im=6A 答案: 答案:A
题型:选择题 After the train crash, the station was a ________ of absolute panic.[ ]A. scenery B. sceneC. sighting D. sign 查看答案
题型:选择题 —How’s your tour around the North Lake? Is it beautiful?—It be, but it is now heavily polluted.A.willB.wouldC.shouldD.must 查看答案