柴油发动机可以使用植物油作为燃料，这将极大地促进使用该技术的国家的农业发展。

Boundaries define us. They define what is me and what is not me. A boundary shows me where I end and someone else begins, leading me to a sense of ownership.

我们所要做的就是记住要勇敢。

沉默是艺术中最响亮的声音。