The Arctic Circle …… through northern North America, Europe and Asia.

Earth’s gravity pulls everything toward …… the Earth.

The forces ….. earthquakes are the same ones that build mountains.

Since the eighteenth century, ….. the major genre of literature in most literate societies.

Under a microscope, ….. of a computer chip looks like a network of aluminum tracks.

Dinosaurs became extinct 64 million years ….. first people ever appeared on Earth.

Venus is almost the same size as the Earth, ….. mountain ranges are much higher.

In concrete poetry the primary consideration is the way that ….. in the poem.

Scientists are now only beginning to understand the factors ….. cigarette addictions.

Agricultural ….. largely responsible for the unfolding of nutritional knowledge of vitamins and minerals early in the last century.

Each summer the Roanoke Historical Association sponsors a play that shows ….. about the fate of the early colony.

Agriculture requires a steady supply of water to keep the plants alive, so ….. in areas with a lot of rainfall.

Even though ….. about $4,000 to fully train a hearing dog, these dogs are generally given without charge to qualified candidates.

The reactor core of a nuclear reactor is housed in a steel vessel ….. by a thick layer of concrete.

Kansas ….. at the geographical center of the United States.

Polar winters are length, dark, and cold enough to kill  plants.

The remains of very ancient wood have turn into coal.

In 1893, Henry Ford built his first car engine in he home workshop in Detroit.

Armies of laborers toiled for eight year to build the Erie Canal.

Some of the stars in the closing stages of their lives becomes while dwarfs.

The normally force of gravity at the Earth’s surface is called 1G.

Edward McDowell is remember as the composer of such perennial favorites as “To a Wild Rose”.

Because he is gravitationally bound to the Milky Way, the Andromeda galaxy is currently approaching Earth.

CAT scanners are used not only for detecting conditions but also for observation the effects of therapy.

The chain of rider stations along the way were crucial to the success of the Pony Express.

The functional relationship between the brain’s two hemispheres has been a major focus of much studies in neuropsychology.

The Great Salt Lake is the remnant of a vast inland seas.

A desire to eradicate irregular spellings in English can being traced back to the sixteenth century.

Jade can actually refer to either the less valuable jadeite and the more common nephrite.

The number of electrons in an atom match the number of charged particles, or protons.

When someone take a depressant, the level of activity in the central nervous system is lowered.

During their first attempts as a songwriter, George Gershwin diligently continued to study the piano, harmony, theory, and orchestration.

Alexander Graham Bell was twenty-nine when him was granted a telephone patent in 1876.

The world’s largest deposits of asbestos have be located in the Appalachian Mountains.

A huge amount of immigrants passed through the Great Hall on Ellis Island between 1892 and 1954.

The cliff dwellings in Mesa Verde were build in the thirteenth century by Native Americans who farmed the green plateau.

The poet Wall Whitman were an easily recognized figure with his long, white beard and wide-brimmed hat.

The sand dollars are a distinctive group of sea urchins that have adapt especially to lie on sandy shores.

Someone who personifies the “American Dream” are Andrew Carnegie, who immigrated to the United States from Scotland without money and made millions in the steel industry.

The Nez Perce lived peacefully with the trappers and traders who traveled theirs lands until the discovery of gold in 1860 brought miners and settlers into region.