---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 |
Would it be ______ for you to pick me up at four o’clock and take me to the airport?
| A．free | B．useful | C．handy | D．convenient |
When I opened the door I found my son completely ______ a game.
| A．absorbing in | B．absorbed to | C．absorbed in | D．absorbing to |
______ it rains tomorrow, they’ll go out for an outing.
| A．As if | B．As though | C．Even if | D．Even so |
Our car ______ on our way to school, so we had to walk there.
| A．broke up | B．broke off | C．broke down | D．broke away |
Wang Ping found the new surroundings difficult ______.
| A．to tolerate | B．to be tolerated | C．tolerating | D．being tolerated |