Define light- year and explain how and why light- years are used to measure distances in the universe

Based on what you know about the location of the earth in relation to the sun, why is this called the goldilocks zone in other galaxies?

What evidence does the writer give to support his argument about coral reefs? a) he speaks of the activities of coral polyps. b) he describes the composition of the great barrier reef. c) he emphasizes the ways in which coral reefs are fragile. d) he points out the ways that scientists do research on the reefs.

Why is oman trying to develop its tourism and manufacturing sectors?