Birds have air sacs and lungs. When birds breathe (in / out,) oxygen-rich air fills the
lungs and air sacs. When birds breathe
(in / out), the oxygen-poor air leaves the
lungs, and stored fresh air enters the lungs from
the air sacs. This means that birds always have a
supply of oxygen-(rich / poor) air.

This is collection of data made by comparing objects in standard units. in science, the units are metric.

Which of the following observation darwin shape his concept of descent with modification? a) species diversity declines farther from the equator. b) fewer species live on islands than on the nearest continents. c) birds live on islands located farther from the mainland than the bird's maximum nonstop flight distance. d) south american temperate plants are more similar to the tropical plants of south america than to the temperate plants of europe. e) earthquakes reshape life by causing mass extinctions.

How do temperature and salinity affect deepwater currents? 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. 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 density differences that cause dense deepwater currents to flow toward the equator where they displace less dense, warmer water above them. they equalize the forces on undersea currents caused by the coriolis effect as they replace more dense water with less dense water.