Most living organisms need to take in oxygen to survive. What is responsible for providing most of this oxygen?
fish and phytoplankton
plants and seaweed
seaweed and phytoplankton
coral and fish

Nasa scientists must work together to make sure that everything is correct and accounted for when launching a shuttle. besides a physicist, what other type of scientist would be in making sure that the shuttle has the appropriate type and amount of fuel to reach its destination?

Which of the following is a good strategy when it comes to desserts

Which member of the following food chain will be least affected by ddt, a pesticide water pollutant, if bio-magnification is occurring? algae> zooplankton> crayfish> leopard frog> large mouth bass