問題詳情
20. In addition to seeds, which of the following characteristics is unique to the seed-producing plants?
(A) Sporopollenin (a component of spore outer walls)
(B) Lignin present in cell walls
(C) Megaphylls
(D) Pollen
參考答案
答案：[無官方正解]
難度：計算中-1
書單：沒有書單，新增