Which sources do scientists use to study the interior of Earth? Check all that apply.
Earth's orbit
core samples
O sea level
earthquakes
S waves
rock composition

Which class of molecules contains the amino group, nh2 (a) sugars (b) water (c) proteins (d) hydrocarbons

What is thought to have caused the mass extinction at the end of the cretaceous period?

Elephants in the savanna regions of africa dig holes in dried up river beds to reach water lying just below the surface. these holes provide drinking water for other animals as well. so, without the elephants, many animals might otherwise die from lack of water during the dry season. the location in which the elephants live is an example of a/n and the role they play in creating water holes is an example of a a) ecosystem; habitat b) community; niche c) habitat; niche d) niche; habitat