The Three Economic Sectors. According to the three-sector theory, all economic activity can be classified into one of three sectors: the primary sector, the secondary sector and thetertiary sector.
It would be tertiary and hospitality i'm pretty sure
Answer:
Scientists used major changes in life forms in the fossil record to form the geologic time scale.
The Orpheus theory, which says that a planet-sized body once collided with Earth and that it sent some of the material into orbit, forming the moon.
