We’ve all been told to dress warmly or we’ll catch cold. But science says the common cold is caused by the virus, not the weather. Actually, according to researchers at Yale University, there just might be something to this old wives’ tale.

For decades, researchers have known that the virus replicates (复制) more readily in cooler environments, such as the nose, rather than at the warmer core body temperature. The reason for this, explains Ellen Foxman, an assistant professor at Yale University School of Medicine, long remained a mystery. Scientists didn’t know whether the virus itself worked better at colder temperatures, or the immune system worked worse. “No one could find anything,” she says.

Then Foxman and her colleagues studied what’s called the born immune system, which is present in every cell, and how it responds to various temperatures when the virus is present. In the lab, they examined airway cells from mice and found that the immune system produced fewer chemical substances called interferons at lower temperatures, allowing the cold virus to flourish.

In a study published this year, they found supporting results in human cells: At the warmer core body temperature, born immune systems that block viral growth are more active, and can stop and kill viruses. Now the team is trying to better understand the defenses the body uses to prevent the virus.

While wearing a scarf around your nose to warm it up might help prevent a cold, Foxman recommends washing your hands so you don’t pass the virus to your eyes, nose, or mouth in the first place. “If the virus isn’t in your nose, it can’t cause infection,” she says.

【小题1】What does the underlined sentence in the first paragraph mean?

A．Listen to the elders.	B．The tale makes sense.
C．The tale is interesting.	D．The research is useless.

【小题2】What did the Foxman team find?

A．The virus increased in warmer environments.

B．The mice was more active in warmer conditions.

C．The immune system produced more antivirus in warm air.

D．A chemical in the immune system can stop and kill virus.

【小题3】What does the Foxman team suggest to prevent the cold?

A．Wearing a scarf.	B．Dressing warmly.
C．Washing the hands.	D．Stay warm in winter.

【小题4】What is the text mainly about?

A．Cold weather causes cold.	B．Tips on protecting immune system.
C．Cold impact the body’s immune system.	D．Many viruses can cause the common cold.