试题题干
Translate the following sentence into Chinese.
Ever since the first farmers arrived in the Midwest almost 200 years ago, cultivation and, consequently, erosion have been depleting the supply of topsoil.
参考答案
试题解析
考点：cultivation 农耕；consequently 因此；deplete 使减少，使枯竭；topsoil 表土。
句子结构：Ever since···为时间状语从句，句子主干为cultivation and erosion have been depleting the supply of topsoil.