请问动名词什么时候用副词修饰 什么时候用形容词

sevengu

1.After gradual declension down to about 39 hours in 1970, the workweek in the United States has steadily increased to the point that the average worker now puts in an estimated 164 extra hours of paid labor a year.
(A) After gradual declension down
(B) Following a gradual declension down
(C) After gradual declining down
(D) After gradually declining（D）
(E) Following gradually declining


oa  d
请问动名词什么时候用副词修饰  什么时候用形容词

Hailee

这是介词短语作状语的用法，跟动名词无关啊