Building a Bridge

Building a Bridge

Bridges go over rivers and lakes. They go over bays and swamps. They go over highways and railroads. Some even float.

Bridges are long and short. They can be high above the water. They can be near the water. They can carry cars, trucks, trains, and buses. Some carry people. Some carry water or oil.

The first bridges were made out of wood, rope, or stone. Today, most bridges are made of steel and concrete.

The first bridges were simple. Some were just logs placed across a stream. Some were ropes stretched across a river.

Later, stones were used to build stronger and longer bridges. In time, people were building bridges like the ones we see today. These are made of concrete and steel. They go across longer distances.