I believe D. because all the organisms that live in a lake can be a bunch of living things that would be considered a population and not a species. I canceled out B. from the get go because, I don’t believe non living organisms can be in a population ?
Please get back to me if I’m right or wrong :)
The equilibrium means that amount that are coming equals the amount that are going.
So the correct answers are
<span>2. A person's income and expenses are equal every month.
</span><span>3. The pressure exerted on the inside of a balloon by the gas inside is equal to the pressure exerted on the outside of the balloon by the atmosphere.</span>
Hydrogen bonds together the atoms in a water molecule. Hope I helped!