What is the significance of the Valley of the Ashes? What images does Fitzgerald use to describe the landscape? How does the setting seem to affect the people who live there? There is a remarkable contrast in the atmosphere of the “valley of the ashes” with the atmosphere of West Egg and East Egg as well as that of Manhattan.

yes the first one is correct .

well stockyards mean a large yard containing pens and sheds, typically adjacent to a slaughterhouse, in which livestock is kept and sorted. and i'm assuming that by party you   mean a large group of people which does make sense because chicago is a very crowded place much like new york. stockyards tend to take up a lot of room due to needing the area for pens to keep animals in and the fact that stockyards are usually right by slaughterhouse where they process and distribute the product. so its much like a zoo but with some dead animal products close by.

by explaining that it took the same total time to travel by plane as it did by train