One of the pedals has come off my bicycle.

我那自行车的踏脚有个已脱落了。

Are good grades a stepping-stone to college?

好的成绩是上大学的踏脚石吗?

She looked on the governorship as a stepping-stone to the presidency.

她把州长之职当作进身总统职的踏脚石。

He found a secure foothold and pulled himself up.

他找到了个稳固的踏脚处并爬了上去。