Because those were the so-called Roaring Twenties. That was the period of extreme wealth, both in the sense of money, and art and culture. Those were the "crazy years", of industrial growth, changes in lifestyle and cure, and of course, the blossoming of jazz music. In that way, the spirit of the whole era was crazy for parties, and thus, Gatsby's parties exemplified exactly that.
Pictures or videos might be used in a speech. It makes it more entertaining.
Answer:
She likes to sleep in, but she can get up early, if she has work.
She can get up early.
She gets up early, because she has work.
Whenever she has work, she gets up early.
