Are receipts a primary or secondary source?

Secondary source

Explanation:

SECONDARY SOURCE MATERIAL. PRIMARY source evidence provides historians with the facts to work with. Journals, documents, contemporary records such as newspapers, receipts, and even material evidence such as clothing or dishes all exist as facts, or Primary Source Evidence

zheng he was a chinese explorer who lead seven great voyages on behalf of the chinese emperor. his seven total voyages were diplomatic, military, and trading ventures, and lasted from 1405 – 1433. however, most historians agree their main purpose was to promote the glory of ming dynasty china.

explanation:

the cost of college has risen faster than inflation for many years.

the high price of student services and administration are two reasons for the rapid increase in cost.