问题
选择题
能使草履虫在水中运动的主要结构是（ ）
A．表膜
B．纤毛
C．口沟
D．食物泡
答案
草履虫是单细胞的动物，通过一个细胞可以完成各项生命活动．其结构及功能如下图
可见，草履虫在水中旋转前进主要依靠纤毛的摆动．
故选：B
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能使草履虫在水中运动的主要结构是（ ）
A．表膜
B．纤毛
C．口沟
D．食物泡
草履虫是单细胞的动物，通过一个细胞可以完成各项生命活动．其结构及功能如下图
可见，草履虫在水中旋转前进主要依靠纤毛的摆动．
故选：B
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