例句與造句

1. The grassland is one of the most important vegetation types in china and the most important renewable resource and raw material site of stock raising . it is a natural green protective screen of the earth which plays an important role to human existence and development
   草地植被是我國最重要的植被類型之一，是重要的可更新資源和畜牧業(yè)的原料基地，又是地球表面天然的綠色屏障，對于人類的生存和發(fā)展起著重要的作用。
2. It's difficult to find raw material site in a sentence. 用raw material site造句挺難的