Memory can decline in old age.

老年时，记忆力可能会有所下降。

His decline in performance worries the teachers.

他的成绩下降让老师们感到担忧。

The statistics indicate a decline in the birth rate.

数据表明出生率在下降。

The birth rate continues to decline in many countries.

许多国家的出生率持续下降。

The decline in fisheries has affected the local economy.

渔业的衰退影响了当地经济。

His decline in performance this semester is very noticeable.

这个学期他的成绩下降得很明显。

The decline in krill populations affects many marine species.

磷虾数量的减少影响了许多海洋物种。

The decline in sales was attributed to the economic downturn.

销售额的下降归因于经济衰退。

The decline in student performance is worrisome for educators.

学生成绩的下降对教育工作者来说是令人担忧的。

The decline in domestic demand has affected production activities.

国内需求的下降影响了生产活动。