过期妊娠应立即终止妊娠的指征有()
A.宫颈条件成熟
B.羊水过少
C.12小时累计胎动少于10次
D.NST阴性
E.CST阳性
参考答案:A, B, C, D, E
I didn't know this ______ he told me. [ ]
A. after
B. before
C. until
D. B and C
设
,B是三阶非零矩阵,且AB=O,则______。
A.当k=1时,r(B)=1 B.当k=-3时,r(B)=1C.当k=1时,r(B)=2 D.当k=-2时,r(B)=2