In this task, you are given a question and an answer, you would be asked to create the sentence based on the Question-Answer provided. It should be contained within the Question-Answer provided.

Question: What is one problem with current methods of aluminum production? Answer: environmental contaminants
Environmental contaminants is one problem with current methods of aluminum production.

Question: What is the process that allows organisms with better traits to survive and produce? Answer: natural selection
Natural selection is the process that allows organisms with better traits to survive and produce.

Question: What do you call an animal in which the embryo, often termed a joey, is born immature and must complete its development outside the mother's body? Answer: marsupial

You call an animal in which the embryo, often termed a joey, is born immature and must complete its development outside the mother's body a(n) marsupial.