Which activates a convection current, starting the flow of a fluid?

A. Cold temperatures at the North Pole

B. Heated liquids at earth's surface

C. iron-rich rocks in the mantle

D. temperature differences in the mantle

Who was one of the founders of the location-sharing site Foursquare? Dennis Crowley Aaron Swartz Josh Williams Scott Raymond Done answer A.

Compact fluorescent light bulbs, hybrid vehicles, and LED light bulbs are all examples of A recycled materials. B energy-efficient technologies. C conservation inventions. D composting.

The tilt of the earth on its axis

What role did the Schutzstaffel, or SS, play in the Nazi Party? a. They were in charge of suppressing revolts. c. They were in charge of propaganda, or advertising, Nazi ideals. b. They served as Adolf Hitler's personal police force. d.

How do weather patterns evolve? What can cause this?

What were some of the examples of the control Kim Jong Il has over the knowledge allowed in North Korea?

What portion of the Earth's surface is too hot, cold, or wet to grow crops?

1. The number and location of bones of many fossil vertebrates are similar to those in living vertebrates. This is evidence in support of which of the following concepts?

What fact or facts support a situation where trade is disadvantageous?

How can you tell that a government is a dictatorship?