8E1 - U7: Getting started

_______ happens when human activities destroy the Earth’s surface.

_______ occurs because there are too many loud sounds in the environment.

When _______ happens, the water temperature in streams, rivers, lakes, or oceans changes.

When radiation goes into the land, air or water, it is called _______.

The sight of too many telephone poles, advertising billboards, overhead power lines, or shop signs may cause _______.

_______ is the contamination of lakes, rivers, oceans, or groundwater, usually by human activities.

_______ occurs when the atmosphere contains gases, dust, or fumes in harmful amounts.

Too much use of electric lights in cities may cause _______.