Which of the following are the elements in the sulfhydryl group? a.)hydrogen and sulfur
b.)carbon, hydrogen, and sulfur
c.)carbon, hydrogen, sulfur and nitrogen

Which of the following must be true for a fossil organism to be useful as an index fossil? a. the fossil organism must be widespread geographically. b. the fossil organism must be abundant. c. the fossil organism must be limited to a short span of geologic time. d. all of the above.

Hydroelectric uses moving water to do work such as grinding grains in a mill true or false

What nerve is affected in bell palsy