2010年3月份,某市市区一周空气质量报告中某项污染指数的数据是:31,35,31,34,30,32,31,这组数据的中位数、众数分别是( )
A:32,31
B:31,32
C:31,31
D:32,35
图1
Eating too much fast food is not ____ ____ our health.