The ozone layer must be protected because it shields the Earth from excessive ultraviolet radiations. 

Despite of rain or snow there are always more than fifty thousand fans at the OSU football games.

When the temperature is risen to the burning point without a source of escape for the heat, spontaneous combustion occurs.

Computer, who keep constant track of inventories and handle all billing, have become the backbone of the large business firms.

When he was a little boy, Mark Twain would walk along the piers, watch the river boats, swimming and fish in the Mississippi, much like his famous character, Tom Sawyer

Pollution, which affects nearly all countries, increase the risk of disease as well as harming the environment.

In the dry season any fishes burrow in the mud and hibernate in a large mud cocoon

Clare Boothe Luce wrote and productioned her first play while she was in high school.

Their silly, whiny conversation on a child level was meant to create tension and heighten Nancy's fears and anxiety.

The soil is composed of a mixture of organic matter called humus and inorganic matter derived from rocks.

A five-thousand-dollars reward was offered for the capture of the escaped criminals.

That once a talented child actress, Shirley Temple Black has established herself as a career diplomat, serving both as a representative in the United Nations and as an ambassador abroad.

Fertilizers are used primarily to enrich the soil and increasing yield.

Gettysburg has been preserve as a national historic monument because it was the site of a major Civil War battle in which many lives were lost.

The most visible remind of the close relationship between the United States and France is the famous Statue of Liberty, which stands in New York harbor.

Papyrus was used for to make not only paper but also sails, baskets, and clothing.

Migraines were usually worse than tension headaches and can be so intense as to cause vomiting and vision problems.

Did they tell you that has in our town an excellent beach less than a mile from the campus?

The Greek historian Herodotus reported that one hundred thousand men are employed for twenty years to build the Great Pyramid at Gizeh.

One can only live without water for about ten days because almost 60 percent of their body is water.

A liter is one of the metric measurements, aren't they?

Overseas telephone service has been expanding fastly since its inauguration in 1927 when a radio circuit was established beteen New York and London

Historically there has been only two major factions in the Republican Party - the liberals and the conservatives.

Some of us have to study their lessons more carefully if we expect to pass this examination.

Before he starting work on the excavation the archaeologist decided to study the maps in the local museum first.

The term Neanderthal man was used to describe widely dispersed populations that lived between 110,000 and 35,000 years ago.

The corals can be divided into three groups, two of which is extinct.

Some conifers, that is, tree that have cones, are able to thrive on poor, thin soil.

John Dewey thought that children will learn better through participating in experiences rather than through listening to lecture.

The patient who was not supposed to be released until the end of the week was told to dress in clothes and report to the nurses' station.