The pyramid entrances had to be facing north. As a result of studying the skies and developing an understanding of astronomy, what other things did the Egyptians invent or make advancements in?

1 and 2

explanation:

i believe

clean air is essential for health and survival

clean air provides nitrogen gas for plant respiration

clean air supplies oxygen that enables living organisms to breathe

hope this

i am brianly

sorry if this doesn't

answer; generalizability;

answer; ancient times;