The secretary said any progress toward improving U.S.-Iran relations will not only be open, but will likely develop slowly.

VOA: standard.2009.05.05

he really did slowly develop a passion for studying languages, at least English.

他真的慢慢开始对学习语言产生热情了，至少是对英语。

留在记忆中的学生 - SpeakingMax英语口语达人

The International Rice Research Institute is working to develop kinds of white rice whose starch is released more slowly.

VOA: special.2010.06.30

Yet their genetics have caused pandas to develop more slowly than human beings and other mammals.

VOA: special.2010.01.19