题目

of the land in that district covered with trees and grass. A . two fifth, is B . two fifths, is C . two fifth, are D . two fifths, are 答案：B某省去年底森林面积为2801700公顷，将2801700用科学记数法表示应为（　　） A、28017×102B、2.8017×106C、28.017×105D、0.28017×107