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.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.