A:②→①→②→③→②
B:②→③→②→①→②
C:③→②→①→②→③
D:①→②→③→②→①
— Yes. She is ____ exchange student from America.
已知⊙O1与⊙O2的半径r1=2、r2=4,若⊙O1与⊙O2的圆心距d=5.则⊙O1与⊙O2的位置关系是____ .