The language is perpetually in flux: it is a living stream, shifting, changing, receiving new strength from a thousand tributaries, losing old forms in the backwaters of time.
语言一直都在变化：那是条流动的溪水，不停地在转换、变换，接受千条支流的新生力量，丢弃旧形式。
2
Under such optimum operating conditions, the changing situation of membrane flux, oil content and COD with time is studied.
在此合理的操作条件下研究了膜通量、含油量、COD随时间的变化情况。
3
The main problem to calculate the emf within a rotating coil is to find out the magnetic flux which is changing with time.