Describe an example where human activities might cause a decline in a population.

If we start o war people will die and the population will decrease. If we pollute the air and water there will be less to drink and eat and there will be more floods. This will cause the population to decrease because there will be more deaths.

The one that would be the most effective means of controlling current water pollution of us surface water is : shutting down factories that discharge materials to the rivers.the largest sum of us pollution currently caused by factory-related substance