【简答题】Water problems in the future will become more intense and more complex. Our increasing population will tremendously increase wastes, primarily sewage. On the other hand, increasing demands for w...
【单选题】Humanity uses a little less than half the water available worldwide. Yet occurences of shortages and droughts (干旱)are causing famine and distress in some areas, and industrial and agricultural by-prod...
A.
The world population is increasing faster and faster.
B.
Half of the world's water resources have been seriously polluted.
C.
Humanity has not placed sufficient value on water resources.