A、human beings B、the mystery C、the sense of smell D、the space C

American researchers have made a discovery that might help them better understand the mysterious sense of smell. VOA’s Jessica Bermon reports. There are about a thousand protein receptors in the nose that tell the brain what it’s smelling. Each receptor can detect one or more odors but scientists have never before linked a specific odor molecule to a particular receptor. Writing in the journal Science, researchers at New York’s Columbia University report doing just that with a meat odor and a receptor in the noses of rats. Steward Fairstine led the team of investigators. He says humans are capable of decerning something like ten thousand different odors. Mr. Fairstine says the reasearch might also tell scientists more about brain chemicals and hormones which are part of the same family as odor receptors. Jessica Bermon, VOA news Washington.