1 . Shyness

Scientists once did a study on two-month-old babies. They ________ that of every five babies, one was very active. This kind of baby liked to make noise. And one of every five babies was always quiet. These babies might be shy when they grew up.

People who are outgoing are sometimes more ________. Shy people may feel that they have a disadvantage. But shyness can be an advantage. Shy people are often very good at listening. This can also make them successful.

3 . Ears at Work

Scientists have been learning more about ears. Until recently, most people thought both ears did the same work. However, studies have shown that the right and left ear work _______. That’s important research. If you are listening to someone speaking, your right ear is reacting（回应）. If you are listening to music, your left ear is more reactive. Researchers think this new information is important in helping people with hearing loss. For example, a student with hearing loss in the right ear might _______ more help in school because the right ear is very important for learning situations.