The crow （乌鸦） is an ordinary （普通的） bird. It is about twenty inches （英寸） long and black all over. Crows are dirty birds because they live on old bad food. Crows eat a lot of waste food. In this way they are more useful to us than any other bird. They clean up the dirty things in our streets. Crows are always hungry. They look for food all day long, and in the evening you can see them in large numbers flying back to their nests (窝) in the trees. They sleep there at night. Crows are much noisier than other birds. Very often a large number of crows will get together on one house and talk. Sometimes they talk together, and sometimes they do it by talking like human beings (人类). It is easy to tell from(区别) crows' sounds whether they are pleased or angry. Perhaps crows talk a lot because they are friendly birds. A pair of crows will live together all their lives, and if one of them dies, the other one becomes very sad and quiet for the rest of its life and sometimes it dies, too.
