题干
It's our_________/'dju:ti/to study hard.
A：dollar
B：duty
C：dinner
D：date
答案(点此获取答案解析）
B
It's our_________/'dju:ti/to study hard.
A：dollar
B：duty
C：dinner
D：date
，若A∩R=Φ，则实数m的取值范围是（ ）
