土壤学 - 2026 进行中
1000 ₸
科目: 土壤学 级别: VII (I级最简单,XII级最难)
类别: 大学生
试题语言: English
题数: 15
问题示例: A soil has a cation-exchange capacity of 25 cmol(+) kg⁻¹ and contains 5 cmol(+) kg⁻¹ of exchangeable calcium. What percentage of the exchange sites is occupied by calcium? 10%, 15%, 20%, 25%