plain saw中文什么意思

例句与用法

1. The average soil fertility rose in the north china plain and mid - lower yangtze river regions , and decreased in the northeast . additionally , although the north china plain saw an improvement in soil ph - value , acidification of the soil increased in the other regions
   土壤肥力数据的分析结果表明，样本总体而言，从80年代初到2000年，除土壤速效钾下降和土壤酸碱性有所退化外，农业上壤的有机质、全氮和速效磷平均含量都增加了。