Your immune system consists of that fight disease.
a. cells
c. organs
b. tissues
d. all of the above

The steps in the formation of extrusive igneous rocks are listed below in an incorrect order: 1. rock melts due to high temperature. 2. rock is buried deep under earth's surface. 3. magma is forced out of earth's surface during volcanic eruption. 4. lava cools and crystallizes to igneous rock. which of these best shows the correct order of steps in the formation of extrusive igneous rocks? 1, 3, 4, 2 2, 1, 3, 4 3, 4, 2, 1 4, 2, 1, 3

In which state was more than 100 billion tons of coal mined in 2005?

When is your breathing likely to speed up? a. when your white blood cells increase b. when your cells need more energy c. when your heart cells need more carbon dioxide d. when your blood cells have too much oxygen