PLEASE HELP WILL GIVE BRAINLIEST Which correctly compares the background extinction rate for mammals to the actual extinction rate over the past 400 years?
A.)45 times higher
B.)25 times higher
C,35 times lower
D.)15 times lower

Which statement is true if the refractive index of medium a is greater than that of medium b? a. total internal reflection is possible when light travels from air to medium b to medium a. b. total internal reflection is possible when light travels from medium a to medium b. c. total internal reflection is possible when light travels from medium b to medium a. d. total internal reflection is possible when light travels from air to medium a. e. total internal reflection is possible when light travels from air to medium b.