Choose the best anwser

17. The man who is ............. over there is my uncle
A. sat               B. sits                 C. sit                D. sitting
21. Of all the students in the class, Nam is the .................
A. best             B. the best          C. good           D. well
22. He failed the exam .................... he was very lazy
A. and              B. but                  C. because     D. although
23. He laughed ............... when he was watching "Tom and Jerry" on TV
A. happy          B. happily            C. happiness  D. unhappy
25. He is interested ............. going to meet their favorite singer
A. in                 B. about               C. at               D. on