The caste system, Buddhism, and the Great Wall.
You can find comprehensive solutions for 5th-grade History workbooks on several educational platforms. Since there are different authors, the "best" answer key depends on which specific workbook you are using. reshebnik po istorii 5 klass po rabochaia tetrad
Regardless of the author, 5th-grade History (History of the Ancient World) typically covers these key areas: The caste system, Buddhism, and the Great Wall