Kepler's third law means that a)All are correct.

b)all orbits with the same semimajor axis have the same period.

c) planets that are farther from the Sun move at slower average speeds than nearer planets.

d) the period of a planet does not depend on its mass.

e) a planet's period does not depend on the eccentricity of its orbit.

The most common economic system in the world is aclosed economy.command economy.mixed market economy.traditional economy.

Air masses are characterized by various properties including temperature humidity air temperature pressure and wind speed . which of the following air masses is associated with low relative humidity and high temperature

Impressions of tropical swamp plants were observed on rocks in polar regions. the impressions were dark black imprints, which means the fossils are examples of ( 1 ) the fossils tell us that polar regions ( 2 ) ( 1 ) a. carbonization b. mineralization c. trace fossils ( 2 ) a. had tropical plants that can grow in ice b. might have had a diffierent climate in the past c. will have abundent vegitation