TASK DEFINITION: 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.
PROBLEM: Question: What type of substance is any matter that has a fixed chemical composition and characteristic properties? Answer: pure chemical substance

SOLUTION: Pure chemical substance type of substance is any matter that has a fixed chemical composition and characteristic properties.

PROBLEM: Question: All species of crocodilians have similar body structures, including an elongated snout, powerful jaws, muscular tail, large protective scales, streamlined body, and eyes and nostrils that are positioned on what? Answer: top of head

SOLUTION: All species of crocodilians have similar body structures, including an elongated snout, powerful jaws, muscular tail, large protective scales, streamlined body, and eyes and nostrils that are positioned on top of head.

PROBLEM: Question: Which characteristic helps some animals defend themselves against predators? Answer: strong odor

SOLUTION:
Strong odor helps some animals defend themselves against predators.