single cropping是什么意思

用法例句

His plays are characterized by singleness and diversity.

这种 意义表现在他剧作的单一与多元两个特点上。

At present, the land utilization in many cities of China is too single, which does harm to interests of resident and hinder the building of inhabitable city seriously.

目前,我国许多城市土地使用过于单一,损害居民利益,严重妨碍城市宜居。

idellus,and Cd had higher single toxicity than PCE.

单一毒性试验表明:四氯乙烯对草鱼24、48、72和96 h的半数致死浓度(LC50)分别为49。