Type the word that appropriately completes each statement.

Most fish have gills that aid in gas exchange. First, water enters the mouth and passes over the gills.
from the water is moved into the blood as
from the blood is moved into the water.

Oxygen from the water

Carbon dioxide from the blood

Explanation:

Fish as any other living organism have the same breathing mechanisms. They breath in oxygen and breath out carbon dioxide.

Oxygen from the water

Carbon dioxide from the blood

Explanation:

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.

if you add everything up correctly you should get 69 i got this because 50 plus 19 is it