睡眠$)=之谜

　　NOVA: Mysterie.$s$ of Sleep Like vir tually every oth*er an]imal, hum
ans n# ee !d sleep to /%survive. Bu#[t why? What ==do we@! gai!n fr;o!m spending ne;+arly a third of our l-+ives !!i! %n such a*%= defe[
)nseles%[
s s(tate!/?$/[ And what's at stake  `i;f we# sleep poo)rly? The($! +functions: of s-leep?# have l[?ong b
een something of
^a mystery. But no \w scien(tis`ts a!@$re pe#,ering deep into the` brain t)o *:se.!e wh( ,a/*t@( happ:ens while we snooze
. _One study reveals )that well-timed bu]rs\ ts of pink !,noise c)+an nudge a person&#:$39s brain waves, e\+xtendin _.g peri! od)s of slow-wave, ^or #d[)e
(ep, s#.leep. A),nd( t(___o):dd^ +l@%_e]rs learning new words /show that taking even a sho!;/rt nap after le*[[=arning something new can help the info,*/rmatio/ n s. tick. And ;when it comes to =sl;`;eeping poorly, it may t
ur*?#^n out that having interrup!ted sleep can be just #?(as h?=.ar@
*mf=*ul``=# as missing%]: ^ sle/ep altogether. As sci
 entists come to understand \the powerful, :/($r#?%ole th^a/+t sleep -- or=\ lack] o_ f (:,it -- p)(, lays in everyt hin]($g from^ mem! ory to tra$;u/! _ma +to emotio! .n regulat/ io`#/n_`, ?\one thing is clear:) This biolog#/:ical function is :as crucial as+ it is [;:co:)mplex.