Ziggurats were tall temples with stairs to the top. Religious ceremonies were held on top. They made the people of the town feel closer to God or gods that they believed in. We now have churches that have pretty much the same purpose.
Irrigation systems were useful because when there was not enough rain for the crops they could get water from the rivers to water the crops. That way the crops would grow and they would have more food for the town and less starvation. We use the same method today.
Sailboats were used for traveled on water. They had sails that you turn the way you want so that the wind catches it and moves you the direction you want to go. They are important because we wouldn't have discovered all the continents and we wouldn't live in america.
The first wheel was very important and still is. They were originally used for chariots for transportation to get people where they want to be fast. Now we use them almost every day with cars to get us where we need to be.
Music was used for religious ceremonies and just for fun. It allowed the people to "talk" to God in different ways other than just praying. We use it pretty much every day now for church, shows, movies, and entertainment.
The Sexagesimal system is a way of writing numbers. It was useful because they could count and do math to figure out what they need to figure out. We use math every day and it is a big part of our lives.