Explain why different stars are seen at different times of night.

Stars are seen at different times of night due to the motion of the Earth in its orbit around the Sun.

Explanation:

When you see stars in night you will see different stars at different times this happens due to the motion of the Earth in its orbit around the Sun.

Each day some stars appear in the east that did not appear before the night. If you measure how much the sky "moves" from one day to the next, you will know that it is about one degree per day.

The "shift" of the sky is actually the motion of the Earth around the Sun.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.

b. climate change will cause an increase in biodiversity of all ecosystems.

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