In my opinion,I think the answer is b.You can control variables more easily by doing different things for different purposes.
A hot air balloon rises in the first place because the air inside is hot, which rises. So, if the air inside is not heated, it fails to rise and falls. Warm air rises because the particles get excited and jiggle with the heat, and cause the air to take up more space. So, as the surrounding air is probably colder and denser, the less dense hot air rises up in the hot air balloon.
Light waves are never 'aborted'.
They can be 'absorbed', and I think that's what you mean.
It's what happens when light hits something or goes into it,
and never comes out.
"Absorb" just means "soak up". When a light wave hits something and
gets soaked up in it, it's gone, and never comes out the other side.
The light wave certainly gets changed ... it no longer exists.
The object that absorbs it also gets changed. It soaks up the energy
in the light wave, and it has a little more internal energy (heat) than it
had before the light hit it.
Answer: the correct option is D (17m).
Explanation: The farthest distance at which a typical "nearsighted" frog can see clearly in air is 17m.
Our sun is quite average when looking at all the stars in the Universe. There are stars that are smaller, like Wolf359, and there are also larger stars, like Betelgeuse. Our sun is essentially right in the middle of the star-size spectrum.
