A:己烷
B:己烯
C:1,2﹣二溴丙烷
D:乙酸乙酯
一星期有7天,四月份有30天,最多____个星期。
已知A,B,C三点在球O的球面上,AB=BC=CA=3,且球心O到平面ABC的距离等于球半径的13,则球O的表面积为____
— Excuse me, are there any book stores around here?
— , but there are some on the Center Street.