Let's break down why:
* fast-slow: These words have opposite meanings, describing speed or pace.
* one-won: These words are related to number and winning, not opposites.
* moving-rushing: These words both describe motion, but "rushing" implies a faster pace than "moving," not an opposite.
* lose-begin: While these words are related to a process, they aren't direct opposites. You can begin something without losing something else.
Therefore, fast-slow is the only pair of words that are true antonyms.