高一英语，求解第三题

Question

如题所述

Answer 1

Costs were reduced by 20% over the past year.
注意减少的词组搭配：
be reduced to XXX% 减少到XXX%
be reduced by XXX% 减少了XXX%
答题不易，满意请采纳！谢谢。

Answer 2

Costs have decreased by 20% over the past year追答

希望可以帮到楼主

Answer 3

have been reduced by 20%

Answer 4

Has reduced 20percent