Which of the following statements about the Earth's atmosphere are correct?
选项：

A:The main components are nitrogen and oxygen.;
B:The atmosphere is mainly divided into three layers: troposphere, stratosphere, ionosphere.;
C:The troposphere, also known as the ozone layer, absorbs the ultraviolet rays of the sun and is a protective layer for life on earth.;
D:The stratosphere is the main place where weather phenomena occur.;
E:Radio waves are propagated by the ionosphere