两圆半径R、r分别是方程x2-3x+2=0的两根,且圆心距d=3,则两圆的位置关系是( )
A:外离
B:外切
C:内含
D:外离或内含
下列生物性状的差异是因变异直接导致的是( )
___________ the guide, the reporter entered the house of the farmer who is famous for
helping other villagers get rich.