---What on earth are the police busy wit
问题:
---What on earth are the police busy with?
---They have been looking into how the plane crash _______.
A.came out
B.came up
C.came down
D.came about
---What on earth are the police busy with?
---They have been looking into how the plane crash _______.
A.came out
B.came up
C.came down
D.came about