— 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

---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

---What on earth are the police busy with?

---They have been looking into how the plane crash _______.

1. A.
   came out
2. B.
   came up
3. C.
   came down
4. D.
   came about

--- What on earth are the police busy with?
--- They have been looking into how the plane crash ______.

1. A.
   came out
2. B.
   came up
3. C.
   came down
4. 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

--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

---What on earth are the police busy with?
---They have been looking into how the plane crash _______.