Some types of lichens have been used to make
a. poison-tipped arrows
b. natural dyes
c. certain foods
d. all of the above

Which of the following is a cost of urbanization? a-cities can provide a high standard of living. b-cities are hubs of entertainment and education. c-paving over land changes the environment. d-job opportunities are greater in urban centers.

Which characteristics are typical of a human population in the postindustrial stage?

What form of anesthetic was used for field surgery