Q1 what are the energy transformations of a fan? a flashlight? burning a little wood?

The motor of a fan works when electric current is passed through it. The electrical energy is then converted into mechanical energy that turns the blades of the fan.

When a flashlight is switched on the chemical energy stored in the battery is first converted to electrical energy that flows through the wire, which then  gets transformed into light and heat energy.

When a little wood burns, the chemical energy stored in the wood gets converted to heat and light energy.

c- cold periods in earth's history during which glaciers covered much of the surface.

explanation:

one negative thing it that it can kill water animals. another negative thing is it can cause the destruction of ecosystem. one way water pollution can be reduced is to conserve energy.