Read and Choose T or F. A hamburger is a kind of sandwich made of some meat inside a bread bun. Lettuce, tomatoes, onions and cheese are often put inside a hamburger, too. People also like to add mustard, ketchup and mayonnaise to make hamburger more delicious. The word "hamburger"comes from"Hamburg, which is the second largest city in Germany. No one knows for sure how hamburgers got their name. Some people say it is because the first hamburgers were made in Hamburg. Other people say it is because some people from Hamburg loved to eat hamburgers when they were in the US. Today, hamburgers are one of the world's most popular foods. They are served in fast-food restaurants all over the world. The most famous hamburger is the Big Mac, which is served at Mcdonald's. Every year around 550 million Big Macs are sold in the US.