精馏

All of us just walked lowering our heads, our sackless legs seemed to get used to this hill road.

早已麻木的双腿似乎已经习惯了这样的山路，众人只是低头行走。

Treatment for mycoplasma should be based on the results of drug sensitivity tests.

支原体的耐药率高，且随着时间的变化，其耐药性也在发生变化。