(  )1. he letter he had been looking forward to ________ at last.
A.arriving      B.arrive     C.arrived        D.being arrived
(  )2. Air pollution often _______ diseases.
A.brings on    B.brings up  C.brings out   D.brings down
(  )3. ________ down the radio, the bady is asleep in the next room.
A.Turning    B.To turn     C.Turned            D.Turn