What new tool/invention made trade across Northern Africa and the Middle East much more possible by 200 A. D? Explain why it made trade possible.

What where the five beliefs of the french philosophers?

Which piece of legislation signed by lyndon johnson brought an end to barriers preventing minorities from participating in elections?

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.