题型:名词解释 教室里投影仪的光源是强光灯泡,发光时必须用风扇给予降温。在使用投影仪时,要求先启动带动风扇的电动机,再使灯泡发光;如果风扇不启动,灯泡就不能发光。图所示的电路图中能符合要求的是:[ ]A.B.C.D. 查看答案
题型:名词解释 He never ____learning English .That was why he was successful at last.[ ]A. gave in B. gave out C. gave up D. gave away 查看答案