There are all kinds of trains in the world. There are trains to carry people, trains to carry animals and trains to carry things.There are fast trains and slow trains. Some trains go under the ground and some trains go through hills.In big cities, the streets are usually very busy. So you can find trains under the ground and trains on a rail above the streets. They carry people in and out of the city.Can a train run over water? Yes, it can. There are many bridges over the river. The trains can easily run over the water. But it is not easy to build bridges.Today's trains have dining rooms for people. You may eat something on the way if you are hungry.