The term "sustained yield" is probably most useful has applied to the yield of well fields in situations that Thomas has termed "water-course aquifers".
“持续开采量”这个术语用于托马斯称作“连河含水层”情况下的井田开采量，大概才是最合适的。
2
In the course of serving tea, the host should take careful note of how much water remaining in the kettle and in the cups of the guests.