单项选择题
A.3/50 B.1/175 C.2/35 D.10/175
A.提高N1660 B.降低N1769 C.降低N1772 D.提高N1783
A.N1606.0=1 B.N1604.0=1 C.N1603.4=1 D.N1401.4=1