45（）
A: up
B: down
C: off
D: back
A: up
B: down
C: off
D: back
举一反三
- A few minutes later, bombs went _______, destroying the car. A: off B: down C: back D: up
- I had to walk back home because my car___ on the way. A: broke down B: broke off C: set up D: set down
- She had been at the company for years and knew all the ___. A: on and off B: up and down C: ins and outs D: back and forth
- We were ______ for an hour in the traffic and so we arrived late. A: kept off B: held up C: put back D: broken down
- Companies can scale ( ) as computing needs increase and then scale ( ) again as demands decrease. A: up,down B: down, up C: on,off D: off, on