Which of the following human activities could have an irreversible effect on an ecosystem? I. introducing a new species
II. urban sprawl
III. introducing a new chemical
IV. over-hunting

answer; i believe that the correct answer is ( rivers);

industry had made the u.s. the richest nation in the world at this time. the second industrial revolution caused growth in industry and transportation, which allowed increased trade between nations.

fertile good for trade etc

answer; deontological theory;