What are the two causes of density in deep current waters?
a. salinity (how much salt) of the water and high temperatures
b. salinity (how much salt) of the water and low temperatures
c. oxygen content of the water and high temperatures
d. oxygen content of the water and low temperatures

Option (B)

Explanation:

The salinity and temperature are two factors that result in the density of the deep ocean current. The salinity refers to the amount of salt present in the seawater.

The temperature of the upper surface of the ocean water is comparatively higher than the lower portion. It is because the upper portion receives direct sunlight from the sun, due to which the temperature increases. As the depth increases, the temperature decreases because sunlight cannot penetrate into the deeper layers.

The depth and salinity are directly proportional to each other, but the temperature and salinity of the seawater is inversely proportional to each other. So the salinity at the deeper part of the ocean is maximum.

Due to these differences in the temperature and salinity content, there occurs the density in the deep ocean water currents.

Thus, the correct answer is option (B).

c

explanation:

blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. as the ventricle contracts, blood leaves the heart through the pulmonic valve, into the pulmonary artery and to the lungs where it is oxygenated.