你吃完面包后，要把桌上的面包屑擦干净。

Nǐ chīwán miànbāo hòu, yào bǎ zhuōshàng de miànbāoxiè cā gānjìng.

After you finish the bread, you need to wipe the bread crumbs off the table.

这点小事，他根本不屑解释。

Zhè diǎn xiǎoshì, tā gēnběn búxiè jiěshì.

He simply disdains to explain such a trivial matter.