四級(jí)無(wú)憂計(jì)劃
主講老師:王江濤、田靜、董仲蠡、潘文婧、衛(wèi)旭、張芷瑜、程之涵
課程特色:小班直播,教師1v1答疑,無(wú)憂換課,免費(fèi)重讀 學(xué)習(xí)群服務(wù) 作文批改 離線看
免費(fèi)試聽
聽課
課程與PC端同步更新,充分利用零碎時(shí)間。做題
海量精選試題,想練就練,瞬間提分。答疑
網(wǎng)校名師24小時(shí)在線答疑解惑直播
名師大咖面對(duì)面,有問有大收獲多。So far, farmers have been able to compensate for the loss of fertile topsoil by applying more chemical fertilizers to their fields; however, while this practice has increased crop yields, it has been devastating for ecology. Agriculture has become one of the biggest polluters of the nation's precious water supply. Rivers, lakes, and underground reserves of water are being filled in and poisoned by soil and chemicals carried by drainage from eroding fields. Furthermore, fertilizers only replenish the soils they do not prevent its loss.
相關(guān)課程
最新文章