Answer:
For instance, I-24 is a primary highway that runs east/west.
Explanation:
Based on information provided by the question, all numbers equal or below 99 are primary highways. If an even number, then it should run from east to west. If the primary highway is an odd number, it means that it runs from north to south. If the number is between 100 - 999, it is an auxiliary highway and the last two digits correspond to the primary highway that it serves.
Answer:
Hydrosphere
I learnt it in Science laboratory
