前置胎盘 * * 出血的特点是()
A.出血量与前置胎盘种类并无关系
B.无诱因、无痛性反复 * * 流血
C.宫缩时出血量增多
D.破膜后仍不止血
E.宫缩时出血量减少
参考答案:B
We can't see the sun _____. [ ]
A. in the day
B. at the night
C. at night
D. in day
下列哪组单位与m/s2等价[ ]
A.N/kg
B.N/m
C.N·m
D.