The weather of this century

(1) The solar eclipse is formed when the moon is just between the sun and the earth, and the earth enters the shadow of the moon, which belongs to the linear propagation phenomenon of light.

(2) Chang 'e-1 satellite orbits the moon and transmits information back to the ground through electromagnetic waves;

(3) The propagation speed of light in vacuum is 3×108m/s;

So, the answer is: linear propagation; Electromagnetic wave; Postgraduate students.