Generally, the sun observes a solar cycle of eleven years. In this cycle, there are fluctuations in the activity, such as the ejected levels of solar radiation, and in the appearance of the sun, such as changes in the amount and size of sun spots, solar flares and other phenomena that occur on the sun's surface.
These changes also affect phenomena on earth, especially the auroras.
2nd choice is the correct one
Cell membranes serve as barriers and gatekeepers. They are semi-permeable, which means that some molecules can diffuse across the lipid bilayer but others cannot.
Radio Waves • have a short wavelength to transfer to your tv and FM radio
Satellite Signals. • Pass easily through the Atmosphere and clouds used for microwaves,Toasters,Remote Controls
