Directions: This question presents a sentence, all or part of which is underlined. Beneath the sentence you will find five ways of phrasing the underlined part. The first of these repeats the original; the other four are different. If you think the original is best, choose the first answer; otherwise choose one of the others.

But the project's overarching goal is to collect DNA from indigenous populations worldwide whose DNA could hold clues to our origins and global migration - and to do it fast, before whole populations die out and leave their ancestral homelands.