問題詳情
13. The veins of leaves are ______.I) composed of xylem and phloemII) continuous with vascular bundles in the stem and rootsIII) finely branched to be in close contact with photosynthesizing cell
(A) only I
(B) only II
(C) only III
(D) I and II
(E) I, II, and III
參考答案
答案：E
難度：適中0.611111
統計：A(1),B(0),C(0),D(3),E(11)