女,40岁,G7P2,停经48天行负压吸宫术,并发症相对较少见的是()
A.子宫穿孔
B.术中出血
C.宫颈粘连
D.宫腔粘连
E.羊水栓塞
参考答案:E
Morgan's parents aren't at home. He has to ______his younger brother.
A.look at
B.look for
C.look after
D.take away
投影器投影成像的位置决定于()
A.反射镜
B.凸透镜(放映物镜)
C.菲涅尔透镜
D.新月镜