1.add to 增加；增添

例句:This latest incident will add to the pressure on the government.
最近的这次事件将会给政府增加压力。

2.speed up 加速

例句:Action had been taken to speed up the release of cheques.
已经采取行动加速支票的发放。

3.promise to 承诺

例句:I'm hoping you'll keep your promise to come for a long visit.
我希望你遵守诺言来这儿多呆几天。

4.expose to 暴露

例句:By bathing in unclean water, they expose themselves to contamination.
在不干净的水中洗澡，他们可能会受到感染。