鸟的身体里有发达的气囊，这些气囊的作用是：_刷题宝

题干

鸟的身体里有发达的气囊，这些气囊的作用是：（）　

A：可减轻身体比重

B：有利于双重呼吸

C：进行气体交换

D：辅助鸟类在飞行中消化食物

上一题下一题 0.0难度选择题更新时间:2016-06-27 02:19:23

答案(点此获取答案解析）

A,B

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