Bài 2 : Chọn đáp án đúng. 1. Every student in those five rooms must bring ........... own books to class. A: one's.             B: someone's.             C: their.             D: his. 2. My aunt speaks English very ................. A: good.               B: well.               C: goodly.             D: best. 3. We have math on Tuesday, Thursday, and Friday: It means we have math ................. a week. A: once.               B: twice.                  C: three times.            D: four times. 4. Peter sometimes helps me ........................ my homework. A: to do.             B: do.            C: doing.                D: are doing. 5. My classroom is ........................ the second floor. A: on.              B: in.              C: at.                         D: of. nhanh nha.