Pls dont have much time
sometimes human actions can have both positive and negative environmental impacts.

a negative impact of a large, hydroelectric dam is that it backs up water sometimes for miles behind it, destroying natural habitat that once was there.

but a positive environmental impact of a dam is that

a.

large amounts of electricity can be produced, without contributing to air pollution

b.

beavers won't build dams of their own

c.

it produces a lake, which is great for water skiing

d.

it makes it easier for migrating fish to make it upstream to reproduce