B. A model cannot show real life conditions. This is so because models aren't alive.
Gravity can be such a tricky subject to talk about I wish I could answer this I need to study more
<span>B) He noticed four-fifths of the air had been used up. If by air this question is referring to oxygen, the fact that it has been used up means it has reacted, mean a substance has combusted.</span>
In electrophoresis, the molecules travel between the positive electrode and the negative electrode carried by the current that is generated between them.
As seen in the image below, short fragments, due to their smaller size can travel faster than the longer fragments, so the fragments that have traveled the furthermost are the shortest. (marked E in the image)