What have the elements of the copper family been used for a. minting coins b. preserving ancient documents c. producing explosives

Give the biological term for: structures that display characteristics of living organisms only within living cells

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water

Abird flies by moving its wings up and down. which two systems are most directly responsible for the movement of a bird's wings? a. skeletal and muscular systems b. respiratory and muscular systems c. skeletal and digestive systems d. respiratory and digestive systems