符合棉花叶枝形态特点的形状有()。
A、只分化叶和腋芽
B、单轴枝
C、二级果枝结铃
D、多着生在主茎的下部
E、叶序左右对生
参考答案:A, B, C, D
简述氮的循环?
As an active participant of his age, Fitzgerald is often acclaimed literary spokesman of the ().
A. Jazz Age
B. Age of Reason
C. Lost Generation
D. Beat Generation