下列哪种植物需要较多含氮的无机盐（ ）
A：马钤薯
B：花生
C：青菜
D：小麦
解方程：x2﹣2x﹣3=0；
归纳阶段特征是历史学习的重要方法。辽宋夏金元时期反映的显著阶段特征是（ ）
（____）A. There is a school in my village.
（____）B. There is a river on the mountain.
（____）C. There're many animals in the forest.
（____）D. There is a tree behind the building.
（____）E. There is a lake near the house.
