题目内容：

    Heads up! Across the country, sports injuries are a safety concern for young athletes. Now, the American Medical Association (AMA) has a new set of guidelines aimed at protecting players from the danger of concussions- serious injuries caused by a blow to the head.

“By raising awareness of the serious risks associated with concussions and ensuring that the appropriate guidelines are in place, we can reduce the number of young athletes who may return to the game too soon, which can put their health at further risk,” said AMA Board Member Jack Resneck Jr, MD, in a statement.

The policy recommends that young athletes who may have a concussion be taken off the field as soon as possible. Then, they are only to return to their sport with a doctor 's written approval. The policy also sets age-specific rules for health care professionals and athletic organizations in evaluating and caring for concussions.

According to the Center for Disease Control and Prevention (CDC), a concussion is a type of traumatic brain injury (外伤性脑损伤) caused by a bump, or jolt to the head or hit to the body that causes the head and brain to move rapidly back and forth. This type of movement can cause the brain to bounce around or twist inside the skull (颅骨). It can damage brain cells and create chemical changes in the brain.

The CDC says that between 1.6 million and 3.8 million traumatic brain injuries caused by sports and recreation-related activities occur in the U.S. every year. A study from the Center for Injury Research and Policy showed that as many as 40% of high school athletes return to playing before they should. The AMA' S new guidelines should help to bring those numbers down.

1.What should young athletes who may have a concussion do?

A.Avoid using the head. B.Leave the field forever.

C.Get treatment in time. D.Switch to another sport.

2.What does the underlined word “jolt” in Paragraph 4 probably mean?

A.A sudden impact. B.A strict limit.

C.A concrete barrier. D.A permanent damage.

3.What is paragraph 4 mainly about?

A.How the EDC works. B.What causes damage to brain cells.

C.What a concussion is. D.How a concussion can be prevented.

4.Which of the following is the best title for the text?

A.Sports Injuries in the US B.Rules for Safer Play

C.Advice to Athletes D.New Policies for Doctors