题目

DNA is the whole “map” of the human body. It is something that all humans have, and it tells the body what to do. DNA is the reason that we look like our parents, because we get some of the DNA to make our own. People have been trying to understand the human body for a long time. In 1860, Mr. Mendel discovered why we look similar to other people in our family. It is because of small things called “genes（基因）” in our body. In 1953, two scientists, Watson and Crick, found out that those small parts are real messages. They are written in the DNA with a special language. In 1961, an人眼能感觉到的光称为        ，那些人眼无法觉察的光称为        ，如         。