1. American Revolutionary War
   War of 1812
2. Civil War
   War on Terror

The American Civil War lasted from April 12, 1861 to April 9, 1865. During this time, the south seceded from the union to form the Confederate States of America.

1. Robert E. Lee
   Winfield Scott
2. Douglas MacArthur
   George Washington

General George Washington took control of the Continental Army in June 1775 under orders from Congress. During the war, Washington lost more battles than he won.

1. Karl Carstens
   Adolf Hitler
2. Roman Herzog
   Angela Merkel

In 1918, Adolf HItler joined the German Workers' Party. On February 24, 1920, the party changed its name to the National Socialist German Workers' Party, which is also known as the Nazi party.

1. Legislative
   Checks and Balances
2. Judicial
   Executive

The Legislative Branch was establish by Article I of the Constitution. Congress has 100 members, while the House of Representatives has 435 members.

1. Delaware
   Hawaii
2. Montana
   Texas

On December 7, 1787, all 30 delegates at the Delaware Constitutional Convention unanimously voted to ratify the U.S. Constitution. The United States Constitution officially became the law of the land on March 4, 1789 when New Hampshire became the ninth state to ratify it.

1. George Washington
   Ronald Reagan
2. Alexander Hamilton
   Millard Fillmore

The Federalist party and the Democratic-Republican Party were the first American political parties. Other prominent Federalists included John Jay, John Adams, John Marshal, and Rufus King.

1. Bill of Rights
   The Top 10 List
2. Inalienable Rights
   The Declaration of Independence

The First Congress of the United States proposed 12 amendments on September 25, 1789. Only 10 were adopted. Currently, there are 27 amendments to the Constitution.

1. World War I
   World War 2
2. Vietnam War
   War of 1812

The Battle of New Orleans took place on January 8, 1915. It occurred after the United States and Great Britain agreed to end the war with the Treaty of Ghent.

1. Tokyo and Osaka
   Kyoto and Kobe
2. Nagoya and Fukuoka
   Hiroshima and Nagasaki

On August 6, 1945, the United States dropped a bomb nicknamed "Little Boy" on Hiroshima. Three days later, "Fat Man" was dropped on Nagasaki. Over 200,000 people, mostly civilians, were killed in these attacks.

1. Plessy v. Ferguson
   Marbury v. Madison
2. Brown v. Board of Education
   McCulloch v. Maryland

On May 17, 1954, the Supreme Court ruled in Brown v. Board of Education that "separate educational facilities are inherently unequal." All nine Supreme Court justices voted unanimously.

1. Solar eclipse
   Sunblocking
2. Hiding a star
   Lunar eclipse

Lunar eclipses can only occur during a full moon. They happen when Earth's shadow is cast on the moon and the planet is between the moon and the sun.

1. Cell
   Stems
2. Leaves
   Chlorophyll

Joseph Bienaime Caventou and Pierre Joseph Pelletier first isolated chlorophyll in 1817. The name comes from the Greek chloros and phyllon. The latter means yellowish green, while the former means leaf.

1. Screw
   Pulley
2. Lever
   Wedge

There are three classes of levers. Examples of levers include shovels and boat oars.

1. Melts
   Condenses
2. Freezes
   Evaporates

The three main states of matter are solid, liquid, and gas. A liquid that freezes becomes a gas. A gas that condenses becomes a liquid.

1. Hard
   Igneous
2. Metamorphic
   Sedimentary

There are two types of igneous rocks: intrusive and extrusive. Intrusive rocks form below Earth's surface, whereas extrusive rocks are formed on the surface. Examples of igneous rocks are basalt, obsidian, pumice, and granite.

1. Oxygen
   Nitrogen
2. Helium
   Hydrogen

The majority of Earth's atmosphere is made of nitrogen and oxygen. Nitrogen makes up approximately 78 percent of the atmosphere. Oxygen accounts for almost 21 percent.

1. Molecules
   Meniscus
2. Atoms
   Chemicals

In 1897, J.J. Thomson discovered the atom. At the time, he was a physics professor at Cambridge University and made his discovery in the Cavendish Laboratory.

1. Saturn
   Earth
2. Uranus
   Mercury

Mercury orbits the sun every 88 days. It is also the smallest planet in the solar system.

1. Heart
   Lung
2. Spleen
   Kidney

A normal adult heart at rest beats between 60 to 100 beats per minute. It also pumps approximately 2,000 gallons of blood a day.

1. Vinegar
   Olive Oil
2. Water
   Hydrogen Peroxide

About 60 percent of an adult human is water. Water lubricates joints, regulates body temperature, and helps the body perform other essential tasks.

1. 5 square inches
   17 square inches
2. 20 square inches
   173 square inches

The area of a rectangle is calculated by multiplying length times width. A square is a rectangle whose four sides are all the same length.

1. The Quadratic Equation
   The Pythagorean theorem
2. Abel's theorem
   Calculus

In the Pythagorean theorem, a and b represent the two sides of a right triangle that contain the right angle. The c represents the third side, which is called the hypotenuse and is the opposite the right angle.

1. 1
   2
2. 5
   10

A prime number is a positive natural number that is only divisible by itself and 1. A number that can be divided by more than those two numbers is called a composite number.

1. 1/6
   1/4
2. 1/7
   1

Equivalent fractions are two fractions that are the same proportion of a whole. For example, 5/10 is equivalent to 1/2.

1. 1/4
   3/4
2. 1/5
   2/5

To simplify a fraction, divide the top and bottom by a common number. This is also called reducing the fraction.

1. 1
   3
2. 6
   8

A place value is the value of a digit in reference to its position in a number. Only single digit numbers have a place value.

1. 60
   90
2. 120
   240

Babylonians used base 60. The Egyptians borrowed the counting system and used it to split up the day, which is why there are 60 seconds in a minute and 60 minutes in an hour.

1. (-1,-6)
   (0,0)
2. (4, 7)
   (5, -5)

The origin is where the x-axis intersects with the y-axis. If there is a third axis (z), the origin is where all three axes intersect.

1. 5
   6
2. 7
   8

The headquarters of the United States Department of Defense is called The Pentagon because it is five sided. It is located in Arlington, Virginia.

1. Bob
   determinator
2. denominator
   numerator

The bottom part of a fraction is called the denominator. It is number of total parts in a whole.

1. Chair
   Walking
2. The
   Very

Verbs are action words. They can also be altered to show tense.

1. He
   Quickly
2. Candy
   Baa

Onomatopoeia is a word that is formed from a sound. Other examples of onomatopoeia are whoosh, meow, and thud.

1. Simile
   Metaphor
2. Noun
   Article

Similes are used to draw a direct comparison. Metaphors are used to draw indirect comparisons and do not use "like" or "as."

1. Car
   They're
2. Hurry
   She

Contractions are often used in informal writing and in speech. They are a word or phrase that has lost one or more letters in the shortening process.

1. un-
   -ology
2. -ful
   -ish

A prefix is added to the beginning of a word to give it a new meaning. A suffix is added to the end of a word and does the same thing.