Answer:
Evaporation.
Explanation:
Most cases of dropping water levels are simply evaporation, usually caused by higher temperatures in warmer climates.
No choice given but the development of nuclear weapons could be considered a negative consequence of the application of scientific knowledge for example when it was used on Hiroshima and Nagasaki killing and wounding 100's of 1000's of people.
Trench
A long , narrow depression of the sea floor formed where a subdcting plate sinks into the mantle
Hope you get it!
