What is the main function of scales on a fish?
A: to protect the fish

Which two body systems are involved in inhaling oxygen and exhaling carbon dioxide?
A: circulatory and respiratory

Which of these causes the atmosphere to change?
A: increased buildup of greenhouse gases

Hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH) to produce a saltwater solution. What are the products of this chemical reaction?
A:
NaCl and H_{2}O