“临池洗耳”的典故与下列哪一位人物相关?()
A.巢父
B.许由
C.谢灵运
D.陶渊明
参考答案:B
---Xiao Ming, will you take part in the coming National English Speech Contest?
---______, we should catch the precious opportunity.
A.No way.
B.Why not?
C.What for?
D.Why bother?
在击剑比赛中,当甲方运动员的剑击中乙方的导电服时(相当于开关“S甲”闭合),电路导通,乙方指示灯L乙亮;反之当乙方的剑击中甲方的导电服时(相当于开关“S乙”闭合)甲方指示灯L甲亮.图中能反映这种原理的电路是( )