<span>Lipids, Proteins, Carbohydrates, and Nucleic acids are the four main groups.</span>
B, the light should be travelling out of the optically dense medium to the optically less dense medium.
were d to read "... is greater than the critical angle" I'd agree with it. But it doesn't read that way ...
Which leaves b as the only one which I think is true. Which I find a bit odd.
Out of interest, TIR is often used in piping light down optical fibres, among many other applications.
Answer:
the surface is tilted or uneven...
Answer: radio and television
Satellite orbits with an East-West orientation are best used
for communication purposes. The satellite orbit should always be suited for its
purpose. Radio and television are powered by numerous satellites rotating the
Earth from east to west.