土壤学 - 2026 进行中

科目: 土壤学
级别: VII
类别: 大学生
测试题目: 英语
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%