Answer:
hope you like it
Explanation:
Examples of natural systems include: real number system, solar system, and planetary atmosphere circulation systems.
Natural physical systems include the solar system and an animal's digestive system. Human-made physical systems include mechanical systems, optical systems, electrical systems, and combinations of these. The names of these systems come from the type of energy they use.
Similarities:
They contain nematocyst (cells that sting)
some are sessil/free swimming
Some corals have a symbiotic relationship with algae, they need to grow in shallow waters so that light can penetrate for the algae to photosynthesize.
The number of species on Earth tagged at 8.7 million as of 2011.
Answer:
the answer youre looking for is A.
(every object located in the universe emits radiation)
