导致子宫脱垂的最主要原因是()
A.多产
B.先天发育不良
C.缺乏雌激素
D.慢性腹压增加
E.分娩损伤
参考答案:E
Is Jim at home by himself? No, there's another boy with him. [ ]
A. playing
B. play
C. plays
D. to play
关于肉毒杆菌,下列哪项是错误的()
A.产生外毒素
B.兼性需氧
C.严格厌氧
D.革兰染色阳性
E.产生芽胞