Which object has a varying speed?
A a car slowing from 60 m/s to 0 m/s
B a car traveling the speed limit
ca fish moving at 2 m/s for 5 minutes
D a bird flying at 10 m/s for 10 seconds

the skeletons of most mammals reach a certain size and then stop growing. however, many animals, including some mammals, keep growing throughout their lives. kangaroos, for example, just keep growing and growing until they die. also, the longer an animal lives the greater the chance it might catch some deadly disease.

answercollision;