Answer the questions on the sheet that is shown in the picture please.

Look at the photo of the leaf. which term best describes this leaf?

Explain how paleontologists use trilobite fossils as index fossils for various geologic time periods.

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere