How is it that two people facing the same circumstances

can react so differently? Why are some folks buffeted（殴打）

 by the vicissitudes （变迁）of life while others glide through

 them with grace and calm? Are some of us just born more nervous

than others? And if you"re one of them, is there anything

you can do about it?

通过一系列的提问，其实告诉读者这篇文章的重点

要谈的是什么内容。

The key to these questions is the emotional response

we call anxiety.  Unlike hunger or thirst, which build

and dissipate （驱散）in the immediate present, anxiety

is the sort of feeling that sneaks up on you from the day

after tomorrow. It"s supposed to keep you from feeling

 too safe. Without it, few of us would survive.

文章给焦虑作出了描述。

All animals, especially the small, scurrying

kind, appear to feel anxiety. Humans have

felt it since the days they shared the planet

with saber-toothed tigers. (Notice which

species is still around to tell the tale.) But we

live in a particularly anxious age. The initial

shock of Sept. 11 has worn off, and the fear

has lifted, but millions of Americans continue

to share a kind of generalized mass anxiety.

A recent TIME/CNN poll found that eight

months after the event, nearly two-thirds of

Americans think about the terror attacks at

least several times a week. And it doesn"t

take much for all the old fears to come

rushing back. What was surprising about the

recent drumbeat of terror warnings was how

quickly it triggered the anxiety so many of us

thought we had put behind us.

像9.11这样的一些重大的事件，它留给人们的恐慌
和焦虑并不是短时间内可以消除的。 

This is one of the mysteries of anxiety.

While it is a normal response to physical

danger — and can be a useful tool for

focusing the mind when there"s a deadline

looming(海市蜃楼) — anxiety becomes a problem

when it persists too long beyond the

immediate threat. Sometimes there"s an

obvious cause, as with the shell-shocked

soldiers of World War I or the terror-scarred

civilians of the World Trade Center collapse. Other

 times, we don"t know why we can"t stop worrying.

There is certainly a lot of anxiety going around. Anxiety

 disorder —which is what health experts call any anxiety

that persists to the point that it interferes with one"s life —

is the most common mental illness in the U.S. In its various

 forms, ranging from very specific phobias （(病态的)恐惧）

to generalized anxiety disorder, it afflicts 19 million Americans . 

And yet, according to a survey published last January

 by researchers from UCLA, less than 25% of Americans

 with anxiety disorders receive any kind of treatment for

 their condition. "If mental health is the stepchild of the

 health-care system," says Jerilyn Ross, president of the Anxiety

 Disorders Association of America, "then anxiety is the

stepchild of the stepchild."

 （运用一个生动的借喻说明焦虑是何产物）

Sigmund Freud was fascinated with anxiety and recognized

 early on that there is more than one kind. He identified two

 major forms of anxiety: one more biological in nature and

the other more dependent on psychological factors. Unfortunately,

 his followers were so obsessed with his ideas about sex drives

and unresolved conflicts that studies of the physical basis

of anxiety languished.（衰弱）