请选择出表达正确者( ):p=7.600pm 0.05kg/(m)^3 B: rho =7.60times (10)^4+0.41times (10)^3kg/(m)^3-|||-:rho =7.600pm 0.140kg/(m)^3 D rho =(7.60pm 0.08)times (10)^3kg/(m)^3答案:(D)38。请选择出表达正确者( ):p=7.600pm 0.05kg/(m)^3 B: rho =7.60times (10)^4+0.41times (10)^3kg/(m)^3-|||-:rho =7.600pm 0.140kg/(m)^3 D rho =(7.60pm 0.08)times (10)^3kg/(m)^3答案:(C)39。等厚干涉实验中测量牛顿环两个暗纹直径得平方差就是为了: ( )A. 消除回程差 B. 消除干涉级次得不确定性; C. 消除视差; D. 消除暗纹半径测量得不确定性;;