当我们向下跑时，小路变陡了。

The path steepened as we ran ___downhill.

长途爬坡后骑车下坡会带来不可思议的自由感。

Cycling ___downhill after a long climb gives an incredible sense of freedom.

他让汽车滑行下坡以节省燃料。

He coasted the car ___downhill to save fuel.