What does the appearance and disappearance of many species help define? A. climate changes
B. species extinction rates
C. geological time boundaries
D. species appearance rates

5) these are organisms where the genetic material is not bound by a nucleus. they are usually unicellular.

Which of these resources is used worldwide to make construction products, pottery, and porcelain

Many people try to eliminate fat from their diets. which is one reason it is necessary for humans to eat fat? a. eating fat is the fastest way to get energy. b. fat eliminates triglycerides from the body. c. saturated fats clear out the blood vessels. d. fat nerves transmit signals. , this is for apex in summer school.