原发性肾病综合征()
A.发病机理尚未明了
B.占小儿肾病综合征的90%
C.可有水肿、大量蛋白尿
D.激素治疗困难,预后较差
E.可有血尿
参考答案:A, B, C, E
参数估计有( )。
A.点估计
B.区间估计
C.均值估计
D.矩法估计
E.方差估计
Concerning a celestial observation,the azimuth angle is measured from the principal vertical circle to the().
A.Greenwich celestial meridian
B.hour circle of the body
C.local celestial meridian
D.vertical circle of the body