Question

1. what unit of time is based on earths revolution?

hour
year
day
month

Explanation:

The Earth's rotation is the spinning of the Earth around its axis. One complete rotation of the Earth on its axis takes approximately 24 hours, which is defined as a day. A year is based on the Earth's revolution around the Sun. An hour is a division of a day (24 hours in a day). A month can be based on lunar cycles (e.g., synodic month) or other calendar - related definitions.

Answer:

day