It should be formal! (answer b).
The hint in the question is that the city major will attend the ceremony- this tells you that the ceremony will have a more representative, formal character, and will not be an internal celebration among people who know each other (this would make it informal or semi-formal).
Answer:
it help us learn about the world
Explanation:
Huang He is the second longest river in China, after the Yangtze River, and the sixth longest river system in the world at the estimated length of 5,464 km
Extremely simple means very simple and great difference means big differ
They banded together because of the nomadic herders and they rebelled against them. They didn't have direct contact with each other therefor keeping everything peaceful.
hope this helped <3
