1、A period of further economic decline set in during the 1930s
進一步的經濟下跌開始于二十世紀３０年代。

2、A period of further economic decline set in during the 1930s.
進一步的經濟下跌開始于二十世紀３０年代。

3、The first signs of economic decline became visible.
經濟衰退的最初跡象開始顯現(xiàn)出來。

economic decline翻譯