How did the first native americans come to america?

What important discovery was made by edmond halley and alexis clairaut, using newton's ideas of mathematics and gravity? they created the scientific method to outline how science should be conducted. they were able to find the orbit of a comet and predict the year of its return. they discovered the three newest planets--uranus, neptune, and pluto. they explained why objects appear to have color.

Why did the third estate form the national assembly?

After studying the timeline above, what observations can you make about u.s. environmental policy between 1970 and 1996?