电视机的荧光屏上经常有许多灰尘,这主要是因为( )
A:灰尘的自然堆积
B:荧光屏有较强的吸附灰尘的能力
C:电视机工作时,屏表面温度较高,吸附灰尘
D:电视机工作时,屏表面有静电吸附灰尘
His wife is constantly finding ____ (过错)with him,which makes him very angry.
函数f(x)=131-x2的单调增区间是 ____,值域为 ____.