Answer:
3. b. Star's mass
4. A. Earth's rotation
5. A. Canis Major
Step-by-step explanation:
3.
Mass of a star determines its age. A heavy mass star has shorter life than a lower mass star. This is because, a heavier star uses its fuel quickly and collapses under its own gravity.
4.
Every object is moving with respect to each other. Stars are very far and appear to move through out the nigh sky because Earth is rotating on its axis. Thus, as the earth rotates, a different part of the night sky is visible to the observer. It is like the rising of sun and setting. Sun also appears to move in the day time because of the rotation of the Earth. In day time stars not visible due to sun's brightness but in night time, stars are visible. With rotation of Earth, the visible sky appears to move. Earth rotates from West to East, so stars appear to rise from East and set in West.
5.
Entire night sky is divided into 88 areas. These areas are known as constellations. These constellations are identified by patterns formed by connecting bright stars.
Canis Major is a constellation near Orion constellation. The bright stars of Canis Major when connected appear like a dog. Thus, it is known as Orion's dog.