Answer:
The time it takes to transport goods has decreased over time, causing trade to increase.
Explanation: Dude, compare how long it took items to go from here to there back then, and compare it to today. For example, people along the silk road would travel months at a time, sometimes even taking a year just to reach their destination and back. Now compare that to your amazon package you ordered from Japan and came in on same-day delivery.
It takes less time now, so it increases how often the packages arrive. Let me know if you need anymore help.