Complete the following sentence with a (compound) word derived from the one(s) given in bracket.
Farmers are advised to use the newly developed fertilizer to（ ）the soil. (rich)
【正确答案】：ENRICH
【题目解析】：
本题考查动词。
根据空格前的to可知此处需要一个动词。use sth. to do...用某物...。因此空格处应为动词enrich。
句意：建议农民使用新开发的肥料来肥沃土壤。