Answer:
1. to protect china from invaders
2. to symboloze chinas power
3. to show china was a unified kingdom
Step-by-step explanation:
im not 100% sure on the last one, but i do believe its more correct than my other choice which was that it showed respect for ancestors becuase the chinese prayed and created temples as respect. with that being said I went with china was a unified kingdom becuase it became a unified kingdom in 221 b.c. when the great wall was built