– I hear Tom is leaving. –____________ why?
A:And
B:But
C:Or
D:So
“朝秦暮楚”反映了哪一时期的历史现象( )
You use_________ to emphasize(强调)that you are referring to(指的是)one thing.
已知⊙O1和⊙O2的半径长分别是一元二次方程x2﹣6x+8=0的两个根,O1O2=2,则这两个圆的位置关系是( )