—At first I was excited, but later I got and left.
A:interesting
B:interested
C:boring
D:bored
刀的刃部一般比较薄,刀刃对木块产生的力F可分解为如图所示的两个相同的分力F1,F2,下列说法正确的是( )
两圆的半径分别为2和5,圆心距为7,则这两圆的位置关系为