A:/ … but
B:/ … or
C:not … or
D:not … but
— Maggie, what you said may result in serious problems.
— I see. I was just telling the truth.
一Are there lots of storybooks in your room?
一 .They are all on my bookcase.
联系上下文,“她的脸上洋溢着从未有过的欣喜”这句话的含义是( )
①对任意正数a,b,都有f(a)+f(b)=f(ab);
②当x>1时,f(x)<0;
③f(2)=﹣1
(I)求f(1)和 f(14) 的值;
(II)试用单调性定义证明:函数f(x)在(0,+∞)上是减函数;
(III)求满足f(log4x)>2的x的取值集合.