Answer: 4.priests and educated people; warriors; merchants; workers
Explanation:
Solar technologies convert sunlight into electrical energy either through photovoltaic (PV) panels or through mirrors that concentrate solar radiation. This energy can be used to generate electricity or be stored in batteries or thermal storage.
The Apollo-Soyuz Test Project was a joint United States-U.S.S.R. venture to live and work together on a space platform in orbit.