题型:选择题 Before I gave my name he ______, which made me very angry. [ ]A. rang off B. got through C. rang back D. hung on 查看答案
题型:单项选择题 设θ为两楔形野中心轴交角,则两楔形野交角照射时,所选楔形角α为()A.α=90°-(θ/2)B.α=90°+(θ/2)C.α=90°-θD.α=90°+θE.α=(90°-θ)/2 查看答案