You might think the largest library in the world would be in Europe. But it isn’t. It’s in Washington, D.C. It’s called the Library of Congress (国会图书馆). President (总统) John Adams started the library in 1800 for members of Congress. He wanted them to be able to read books about law. The first 740 books were bought in England. They were simply set up in the room where Congress met. Then President Thomas Jefferson sold Congress many of his own books. He felt Congress should have books on all subjects, not just on lag. This idea changed the library forever. The library grew and grew. Now it covers a lot of land. In it there are 20 million books as well as a great number of pictures, movies and machines. Experts (专家) in every field work there. Hundreds of people ring them up every day with all kinds of questions. Many of them get answers right over the phone. What didn’t President Thomas Jefferson do

A. He sold the Congress many of his own books.
B. His idea changed the library forever.
C. He asked many experts to come to the library.