問題詳情
6.tIn the fish gills:
(A)tblood and water flow in opposite directions.
(B)tblood and water flow in the same direction.
(C)tblood flowing in the gills reverses direction with every heartbeat
(D)twater flowing over the glls reverses direction whh every inhalation.
(E) blood and water are separated by a thick polysaccharide barrier.
參考答案
答案：A
統計：A:3,B:0,C:0,D:1,E:0
難度：計算中