Answer:
They are: who, which, whom, what and whose. These are also known as wh-words.
Explanation:
I think it's present participle
One of the most popular quotes about greed in animal farm is <span><em>“The creatures outside looked from pig to man, and from man to pig, and from pig to man again; but already it was impossible to say which was which.”
</em>The quotes is written in a scene where politicians gather together for supper and talk about their desire for power.
And the narrator perceive these politicians as greedy pigs that never feel satisfied.
</span>
If the frequency of the sound is increased then the pitch will also increase.
