为保持土壤肥力,农民搞作物轮作.Farmers rotate their crops so that the soil will remain fertile.农作物轮作有助于防止水土流失.Crop rotation helps prevent soil erosion.他连续5年在同一块地里种植不同的作物，研究人员称之为轮作。He grew a different crop on the same field five years i...
His beautifully illustrated book well attested his love of the university.他那本带有精美插图的书见证了他对大学的热爱。He's just written a book, nicely illustrated and not too technical.他刚写完一本书，插图精美，内容也并不艰涩。The book is well written, prope...