Dogs Can Smell Stress
Dogs have a great sense of smell. We train them to search for missing people or to find bombs（炸弹）. But recently British scientists did an experiment. It led to a new discovery：
How can dogs tell the difference between the smell of a stressed person and that of a relaxed person? But they have a good guess：People might give off a special smell whenever they feel nervous. And dogs can catch that smell with their sharp noses.
It's normal to feel sad, worried or nervous from time to time. The next time. you feel this way, don't be surprised to find that your dog already knows this.
A. The scientists don't know yet.
B. Dogs can smell stress.
C. Do you like your pet dog?
D. You gives off a smell of stress and your dog catch it with its nose.
E. Many dogs enjoy playing ball games with their masters.
F. We have long known this.
G. Life isn't easy for any of us.
