A:是偶函数,在-∞,0是增函数
B:是偶函数,在-∞,0是减函数
C:是奇函数,在-∞,0是增函数
D:是奇函数,在-∞,0是减函数
If someone spends his or her time, effort and money writing a book, for example, he or she deserves _______ for it.
如图所示,阻值为R的电阻丝,用四种方法分别接在电压为U或2U的电源上.闭合开关后,在相同时间内虚线框里的电阻丝产生的总热量最多的是( )