Answer:
a. people had never seen a giant building made of glass before.
A random sample is a subset of individuals that are randomly selected from a population of interest. Because researchers usually cannot obtain data from every single person in a group due to time, costs and other constraints, a smaller portion is randomly chosen to represent the entire group as a whole. The goal is to get a sample that is representative of the larger population.
Benefits - easy to obtain , reliable. drawbacks - bad for environment , theres better alternatives
I would say D) Because swimming races are won by inches, the new suits can make a difference. It's joining a statement and a reason for the statement.