The first devices used to measure time relied on the

One legend says that the first ______ was a farmer's hat tied to a string.

Before coins were invented, people

The Chinese began using flat metal ______ with holes in the center as coins.

_________ comes from the cocoon of a silkworm.

The chinese learned to put cocoons into _____________ to loosen the strands of silk.

_________ cut from wood were used to print short religious texts.

The ancient Chinese people could be described as