Harvey was training for a cross-country bicycle race. during his practice run, harvey's tire went flat and he fell off of his bike, cutting both knees. he was worried that he would not be able to compete in the race being held in two weeks, but his father told him not to worry: his knees would be healed by then. what process is responsible for new tissue growth and the healing of harvey's knees?

correct answer is option a.

tropopause, stratopause and mesopause have all in common aspect that is point of maximum temperature in its layer of the atmosphere. all layers of atmosphere observe abrupt change in temperature. tropopause is the boundary between troposphere and stratosphere. stratopause is the boundary between stratosphere and mesosphere. mesopause is the boundary between mesosphere and thermosphere. these all boundaries are ranges between altitude of 0 to 80 km.