The United States wants South Africa to step up its leadership role in Africa, particularly in the area of trade.

VOA: standard.2009.08.08

The work in this step is just the area under this curve.

而这一步过程的功,是这条曲线下面的面积。

麻省理工公开课 - 热力学与动力学课程节选

and Pembroke area there's a place, "the steps", that if you step on the seal,

在彭布鲁克区，有个地方叫“台阶”，如果你踏在了印记上，

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