Air (66) …………………. can make people (67) ………………….. Consequently, some countries pass (68) …………………. to control the quantity of (69) …………………. in the air. Air pollution causes particular damage to the body by harming the (70) ………………….. (71) …………………. should not be used in petrol because it is bad for children’s (72) …………………. and makes them clumsy in using their hands. Poisonous gas from (73) …………………. collects in those parts of cities where there are tall buildings. Pollution can also have an influence on the earth’s (74) ………………….. The ice may melt near the North and South Poles, resulting in very bad (75) …………………..

A geyser is the result of underground water under the combined conditions of high temperatures and increased pressure beneath the surface of the each. Since temperature rises approximately one degree F for every sixty feet under the earth’s surface, and pressure increases with depth, water that seeps down in cracks and fissures until it reaches very hot rocks in the earth’s interior becomes heated to a temperature in excess of 290 degrees F. Because of the pressure, it shoots out of the surface in the form of steam and hot water. The result is a geyser.
For the most part, geysers are located in three regions of the world: New Zealand, Iceland, and the Yellowstone National Park area of the United States. The most famous geyser in the world is Old Faithful in Yellowstone Park. Old Faithful erupts almost every hour, rising to a height of 125 to 170 feet and expelling more then ten thousand gallons during each eruption