单项选择题
A.0.02√s+0.0006s B.0.01√s+0.0003s C.0.04√s+0.002s D.0.02√s+0.001s
A.N倍; B.N1/2倍; C.N﹣1/2倍; D.N/2倍;
A.50m B.100m C.150m D.200m