yán / jiū / rén / yuán / tōng / guò / tǔ / rǎng / pōu / miàn / guān / chá / lín / róng / céng / de / hòu / dù研究人员通过土壤剖面观察淋溶层的厚度。Researchers examined the thickness of the leached layer through a soil profile.