21. I must go _______ a diet. I put _______ a lot of weight while I was on vacation. A. through / off B. round / away C. for / with D. on / on 22. What do the initials USA stand _______? A. up B. on C. for D. with 23. Livy’s getting _______ very well in Russian. She takes _______ practicing the language every day. A. up / off B. on / to C. through / in D. in / up 24. The airhostess asked the passengers to do _______ the seat-belt before the plane took _______. A. up / off B. on / away C. over / in D. for / up 25. The fireworks went _______ in all their colors and lit _______ the sky. A. off / up B. upon / beyond C. among / in D. up / of 26. So many people were absent that we had to call _______ the meeting. A. on B. with C. off D. in 27. He came _______ some of his old love letters in his wife’s drawer. A. forward B. along C. across D. up 28. I had to stand _______ for the boss while she went _______ A. of / round B. up / over C. in / away D. on / ahead 29. Don’t worry, the pain should wear _______ fairly soon. You will get _______ your illness. A. on / through B. off / over C. for / with D. in / for 30. I have to send _______ a tow truck because my car broke _______ A. for / down B. under / of C. up / into D. in / off