单项选择题
A.容易预测的 B.可以预测的,但很难精确预测 C.不可能预测的 D.以上都不对
A.0.02%,0.04% B.0.03%,0.03% C.0.02%,0.03% D.0.03%,0.04%
A.0.3 B.0.6 C.0.09 D.0.15