The critical angle at the boundary between a ruby and the air is 34.6º. Use this to calculate the refractive index of this ruby. Give your answer to
two decimal places.

Which lists the main components of darwin’s theory of evolution? a. random mutations drive evolution; the evolution of a population happens slowly; organisms have common ancestors; organisms do not change. b. natural selection drives evolution; the evolution of a population happens slowly; organisms have common ancestors; organisms change over time. c. natural selection drives evolution; the evolution of a population happens rapidly; organisms have common ancestors; organisms change over time. d. random mutations drive evolution; the evolution of a population happens rapidly; organisms have common ancestors; organisms do not change.

Which lists the organs in the correct order as food passes from the mouth to anus?

True or false graphs must include scales that increase by the same amount