Describe how humans might be contributing to a higher extinction rate than was seen in the past.

According to the online content activity for this lesson, what should you do if you do not understand the material you are trying to learn? a. try a new approach to learning the material. c. re-read the material b. give up d. find someone to give you the answers to the test select the best answer from the choices provided a b c d

What statement is true about all chemical changes? a) chemical changes can be undone. b) chemical changes cannot be reversed. c) chemical changes change the color of objects. eliminate d) chemical changes do not form new products.

Select the correct answer. what was edwin hubble's contribution to the field of astronomy? a. he discovered variable stars. b. he proved that the heliocentric model accurately described our solar system. c. he found a relationship between the period luminosity and distance of stars. d. he proved that the universe is finite. e. he discovered that the universe was expanding.