oxygen can be found in air & an animal / bacterium requires oxygen for survival / to breathe ->  an animal requires air for survival  an animal requires air for survival & animals / living things require water for survival ->  an animal requires water and air for suvival  an animal / living thing requires nutrients for survival & an animal needs to eat food for nutrients ->  an animal requires food for survival  an animal requires water and air for suvival & an animal requires food for survival -> an animal requires water and air and food for survival