1) The ozone layer, located in the Earth's stratosphere, protects us from harmful ultraviolet (UV) radiation.

2) The Grand Canyon, located in Arizona, United States, is a massive and awe-inspiring natural formation carved by the Colorado River. It is approximately 446 kilometers (277 miles) long, up to 29 kilometers (18 miles) wide, and reaches a depth of over 1.8 kilometers (1.1 miles).

3) Political campaigns involve strategic activities, such as advertising, public appearances, and grassroots organizing, aimed at promoting a candidate or political party and gaining support during elections.

4) The Earth's core is primarily composed of iron and nickel and is as hot as the surface of the sun.