difference structure的用法和樣例：
例句
- Study on Design of Sloping Stable Forest Structure in Hilly-Gullied Area of Loess Plateau.
黃土丘陵溝壑區坡面穩定林分結構設計研究。 - Undergrowth, one important component of the forest ecosystem, plays an important role in maintaining the forest structure and soil quality.
林下植被作為森林生態(tài)系統的一個(gè)重要組成部分，對維持林分結構和土壤質(zhì)量起著(zhù)重要作用。
