21. Kids have to walk fast if they want to ….. their parents on a stroll through the park.
A. keep with B. keep up with C. in D. off
22. She kept …….. taking the real estate exam until she funally passed it and got her license.
A. on B. onto C. in D. at
23. Some men never grow …… . They act like little spoiled boys their whole lives.
A. out B. on C. up D. over
24. If you are going to give…… smoking , you must have a lot of will power.
A. awy B. up C. into D. off