Unlike freshwater fish, saltwater fish
a. often contain a lower concentration of salt than the water they live in.
b. tend to gain water from their surroundings.
c. would swell if they didn't conserve water.
d. would swell if they didn't eliminate salt.

The best answer is A

Saltwater fish are hypotonic to their surroundings. This means their blood has a higher water concentration than the surrounding sea water.

Due to the fact that there is more salt and less water outside their bodies, there is a tendency to take in salt and lose water.

To counter this, salt water fish drink a lot of the sea water and urinate very little. Special cells in the gills actively eliminate salt at the cost of extra energy and these fishes do not absorb any salt from the water they drink.

burning of wood and coal

explanation:

the panel also concluded there's a better than 95 percent probability that human-produced greenhouse gases such as carbon dioxide, methane and nitrous oxide have caused much of the observed increase in earth's temperatures over the past 50 years.

what statement best describes the difference between the sympathetic and parasympathetic nervous systems?

the sympathetic nervous system prepares the body for intense physical activity and is often referred to as the fight-or-flight response. the parasympathetic nervous system has almost the exact opposite effect and relaxes the body and inhibits or slows many high energy functions.