He stepped back several times to make sure the picture was really straight.

他来回看看，以确认这幅画已经挂好了。

After Kelly's dad dies, Grandpa Wilfred steps up big time.

在凯莉的父亲去世后, 爷爷威尔弗雷德大踏步前进。

And here they come 'cause you done stepped in too many times.

他们来了，因为你介入太多次了。

The mean of the binomial distribution is essentially the probability of taking a left step times the total number of trials.

二项式分布的均值本质上是左步概率乘以试验总数。