题目

For decades，childhood obesity rates have been on the rise.Now some US cities，including Philadelphia，New York City and Los Angeles，are seeing progress in their fight against obesity.Dropping childhood obesity rates have also been reported in parts of Mississippi，the state with the highest obesity rate in the nation. The first drops in the number of overweight children came in a September report by the Robert Wood Johnson Foundation.The foundation works to improve health for Americans.New York City showed a 5.5% drop in the number of overweight children from 2007 to 2011.Philad下列说法中，正确的是A.零是最小的整数B.零是最小的正数C.零没有倒数D.零没有绝对值