Lack of Sleep Is Dangerous

          Do you know that if you miss out too much sleep you will die? It's true! If you stay awake for a long, long time, your brain and body will break down.

The unofficial world record for staying awake is 11 days, and it's held by Randy Gardner. [A1]_______  He also had help from TV and radio reporters, a sleep researcher and a doctor.

          What happened ? ___ [A2]_________ Then his brain started to lose sense. On day 4, he thought a street sign was really a person. On day 6, he began to speak very slowly. On day 9, he couldn’t finish sentences. On ty 10, Randy thought he saw a forest in the next room.  ____ [A3]__________Eventually, after  he'd broken the world record, Randy was told to go to sleep.Experiments that keep people awake for dangerously long periods are always stopped before the patients break down .

          Rats, however . aren’t so well cared for. ____ [A4]__________That's sooner than if they'd been allowed to sleep but were given no food. They get really thin. But that’s not because se they stop eating—quite the opposite. Even though these rats are eating food, their bodies can't process it in the normal way. On top of that, their little bodies lose more heat than normal, which makes them weak. This means that they need more food to stay at a healthy temperature.  __ [A5]__________ 

And that's what lack of sleep does for you.

A. In fact, he went a bit crazy.

B. Normally rats wouldn't catch a cold.

C. Towards the end, the health of these rats is failing.

D. When kept from sleeping, they die within three weeks.

E. Randy asked two of his friends to stop him falling asleep.

F. First of all staying awake long made Randy bad-tempered.