Answer:
STAGE 1: AN INTERSTELLAR CLOUD.
STAGE 2: A COLLAPSING CLOUD FRAGMENT.
STAGE 3: FRAGMENTATION CEASES.
STAGE 4: A PROTOSTAR.
STAGE 5: PROTOSTELLAR EVOLUTION.
STAGE 6: A NEWBORN STAR.
STAGE 7: THE MAIN SEQUENCE AT LAST.
1. Giant gas cloud
2. photostar
3. T-Tauri phase
4.Main sequence
5.Red giant
6.The fusion of heavier elements
7.Supernova and planetary nebulae
