I think the answer is c but I looked it up and got this: system or thing used as an example to follow or imitate.
<u>Answer</u>:
The mass of a star can be determined by studying binary star systems.
<u>Explanation</u>:
In this system it consists of two stars, revolving round the same bary-centre. The systems having two or may say more than two are called as the multiple star system. This zone is also a habitable zone, here the water exists in the liquid form. We could have sometime seen the two stars together. They are also very capable of strengthening the terrestrial planets inside the stable orbital ranges. They have generally two orbits like P-type as well as circumbinary.
A) a common ancestor
Homologous structures are structures that are similar in related organisms. There is a basic pattern of bones which can be inherited from a common ancestor
The endocrine system uses chemicals
The water moves to form a solvent for the glucose.
