Which type of rock may contain fossils?

Fungi are classified into how many groups? a. 1 group b. 2 groups c. 3 groups d. 4 groups

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

What is the next step in muscle contraction after the actin changes shape