It’s an ordinary day. You may be entirely relaxed, settling down to watch some TV. Suddenly you begin to feel scared. Everything around you is becoming unreal. Your heart is racing, your head spinning, your handsshaking. An overwhelming sense of despair and pain hits you like a wave. What on earth is going on?If you have ever had an experience like this, it’s possible that you were having a “panic attack”. Some people experience panic attacks in tense situations, such as before giving a speech. For others it comes completely unexpectedly. But a panic attack is a very real condition, and not at all the same thing as just getting upset and confused. So what causes it?Panic attacks begin in the oldest parts of our brain. Before we had evolved rational thought, we still needed to be able to survive in the world. The ability to either fight or flee from a dangerous situation is perhaps the most basic behavior required of any animal.Panic attacks occur when the body systems responsible for dealing with dangerous situations kick in at the wrong time. There is no danger in relaxing on your couch, and no real danger in giving a speech. But in some people, the “fight or flight” responses can be provoked accidentally. Heart rate increases, breathing becomes shallow, and adrenaline shoots to your arms. These are useful responses to have, if you really are in danger. For people who experience a panic attack, though, they can be both confusing and terrifying.Several different therapies now exist for panic attacks, ranging from a set of anti-anxiety medicines to behavior modification. So take heart—there’s no need to panic.New words:adrenaline n.肾上腺素1.When are people likely to experience a “panic attack” according to the speaker?A) When they are scared by someone.B) Right before they give a speech.C) When they feel upset at something.D) Right before they are attacked.2.What basic ability do we have to survive a dangerous situation?A) The ability to sense tense situations.B) The ability to either fight or flee.C) The ability to behave yourself.D) The ability to avoid confusion.3.Why do panic attacks occur while no real danger exists?A) Because the “fight or flight” responses kick in at the wrong time.B) Because heart rate increases and breathing becomes shallow.C) Because you feel that you are really in dangerous situations.D) Because you feel confused and scared from the situations.4.How could one deal with a “panic attack” according to the speaker?A) By taking anti-depression medication.B) By staying away from panic attacks.C) By taking heart for your situation and no worry.D) By keeping your heart rate down.