How many major ice ages have there been in the last 800 million years?

the eggs of the insects should be the first thing collected at the scene.

false

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

dna is a set of a gene held together by a chemical bond