Which of the following characteristics of living things best explains why some North American birds fly
south for the winter?
a. Living things respond to their environment.
b. Living things maintain internal balance.
c. Living things are made up of units called cells.
d. Living things are bazed on a universal genetic code.

How do temperature and salinity affect deepwater currents? question 15 options: as temperatures and salinity levels of water increase, the water rises to the surface where it creates currents as it moves to colder regions. they create changes in wind direction, moving denser water in the same direction as the wind and causing the deepwater circulation patterns found in the ocean. they equalize the forces on undersea currents caused by the coriolis effect as they replace more dense water with less dense water. they create density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them.