世界上最大的平原是( )
A.西西伯利亚平原
B.东欧平原
C.东北平原
D.亚马孙平原
世界上面积最大的平原是位于南美洲的亚马孙平原.
故选:D.
Liu Fang is a company CEO now, but she ____ as a teacher in a middle school for three years.
A.worked
B.has worked
C.works
D.had worked
急性腹膜炎发生严重休克的主要因素为
A.水和电解质紊乱
B.血容量减少和吸收大量毒素
C.腹腔内有无原发病灶
D.发病年龄不同
E.腹膜有无刺激征