产后出血原因当中，首先考虑以切除子宫止血的项目是（）.
A.宫缩乏力
B.胎盘植入
C.胎盘嵌顿
D.胎盘粘连
E.凝血功能障碍
参考答案：B
He was in the mountain for a year. He felt as if he was ________ from the outside world.
A．cut out
B．cut in
C．cut off
D．cut up
二化螟属（）目、（）科的水稻害虫。
