疲惫的登山者在岩石上突然瘫坐下来。

The exhausted hiker ___slumped suddenly onto the rock.

疲惫的学生在课桌上无精打采地趴着。

The tired student was ___slumping over his desk.

由于经济不景气，这家公司的销售额大幅下滑。

The company's sales ___slumped due to the economic downturn.