土地自然分类系统一般按()为具体标志进行分类。
A.土地适宜性
B.土地的覆盖特征
C.地貌
D.植被
E.土壤
参考答案:C, D, E
I became a student ten years . I have been a student 1996. I have studied here_____ about 10 years.
A. ago, since, for B. ago ,for ,since, C. ago, before, for D ago, in, after
简述开展社区营养工作资料获得的途径。