21. Boys! Put your toys ______. It is time to go to bed. Don't stay _____ late.
a. off / on b. away / up c. down / off d. around/ for
22. She intended to quit her job to stay _______ home and look _______ her sick mother.
a. in / at b. at / after c. for / over d. up / on
23. He is very worried _______ his new job because he is not quite prepared _______ working.
a. on / over b. to / off c. about / for d. in / at