The cretaceous-tertiary extinction, the most famous of all the big five, has been attributed to what major event that triggered the fall of the dinosaurs? an asteroid hitting the earth increased competition from mammals rapid growth of forests on land surfaces glaciation

The most popular explanation for the extinction of the dinosaurs was an asteroid hitting the Earth.

A piece of evidence for this is a layer of rock with properties similar to those found in an asteroid that falls in line with when the dinosaur extinction occurred.

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native american contribution: the patriots from britain learn how to hunt, fish, and introduce diversity within cultures.

african americans: indirectly introduced the idea of diversity to americans. africans coming to america because of slavery taught white americans that people come from different backgrounds and colors. it also built america's economic stability for a great period of time. 

women: make america what it is today. there are some societies that are in the world currently that do not give women the same right we give women here in the united states. because women have rights here in the united states, other countries' citizens strive to come to america, especially women, since they have equal rights in the united states. this is important because america is seen and desired by many in the world. 

children: children are our future. we learn from our elders and carry out things the same or differently learning from america's history. we continue tradition and change tradition if it is needed. 

athenian democracy developed around the fifth century bc in the greek city-state (known as a polis) of athens, comprising the city of athens and the surrounding territory of attica, and is often described as the first known democracy in the world. other greek cities set up democracies, most following the athenian model, but none are as well documented as athens'.

it was a political system of direct democracy, in which participating citizens voted directly on legislation and executive bills. participation was not open to all residents: to vote one had to be an adult, male citizen, i.e., not a foreign resident, a submissive or a woman, and the number of these was "probably no more than 30 percent of the total adult population."[1]

the longest-lasting democratic leader was pericles. after his death, athenian democracy was twice briefly interrupted by oligarchic revolutions towards the end of the peloponnesian war. it was modified somewhat after it was restored under eucleides; the most detailed accounts of the system are of this fourth-century modification rather than the periclean system. democracy was suppressed by the macedonians in 322 bc. the athenian institutions were later revived, but how close they were to a real democracy is debatable. solon (594 bc), cleisthenes (508/7 bc), and ephialtes (462 bc) contributed to the development of athenian democracy. cleisthenes broke up the power of the nobility by organizing citizens into ten groups based on where they lived rather than on their wealth.

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