2岁以后血液中胎儿血红蛋白(HbF)水平是()
A.HbF<30%
B.HbF<20%
C.HbF<10%
D.HbF<5%
E.HbF<2%
参考答案:E
catch the first bus to the Great Wall, we get up early.
A.In order
B.In order to
C.In order that
D.So that
能对污染源进行综合评价的指标是()
A.超标率
B.等标污染负荷
C.污染物的排放浓度
D.超标倍数
E.污染物的排放体积