Do you know why you sleep?You may think it's because you're tired．Or perhaps you've been told sleep is good for you．Yet no one knows exactly why or how people sleep．
Until the early 1950s, most scientists thought the body and the brain rested during sleep．Then a scientist watched people sleep．He noticed that during periods of between 5 and 30 minutes, sleepers' eyes made rapid movements, as if they were watching something．He called these periods REM(Rapid Eye Movement)sleep．He called periods when sleepers' eyes did not move non-REM sleep．
Whenever the scientist woke people during REM sleep, they were having vivid dreams．Measurements(测量)showed that sleepers' pulses(脉搏)went up quickly during REM sleep．Their breathing, heartbeat, and the blood going to the brain also increased．Far from being a time of rest, REM sleep is a time when the body is hard at work．Scientists still don't know the reason for this．Some believe REM sleep helps the brain grow．Others think REM sleep is a time for the brain to empty the day's garbage．
One thing all the scientists agree on is that sleep is necessary．Without enough sleep, people make mistakes．Most car accidents happen during the early morning hours when people are sleepiest．
(1)
During REM sleep, a person's breathing and heartbeat ________．
[ ]
A．
stop
B．
sleep
C．
increase
D．
stay the same
(2)
The underlined word“vivid”means ________．
[ ]
A．
easier
B．
large
C．
empty
D．
clear anti lively
(3)
________ tells what happens when people don't get enough sleep．
[ ]
A．
Paragraph 1
B．
Paragraph 2
C．
Paragraph 3
D．
Paragraph 4
(4)
The main idea of this passage is ________．
[ ]
A．
that REM sleep can help the brain grow
B．
about the scientific research of REM sleep
C．
about how to empty the day's garbage
D．
that our body is good at work when sleeping
(5)
We can know from the passage that ________．
[ ]
A．
enough sleep is very important to people
B．
young people can experience REM sleep
C．
the speed of sleepers' pulses will slow down during the REM sleep
How many books are students allowed to borrow at once? Kindergarten and Grade One：Children are allowed to borrow one book a week．Grade Two and Up：Students in Grade Two and up are allowed to borrow two books a week．
How long is the loan? Books are loaned for about a week，however the school is on a 5-day cycle．Books are due on the cycle day．A book borrowed on Day 1 is due on the next Day 1，even if it is not the same day of the week．A book borrowed on Tuesday may be due on a Wednesday，if there is a holiday between when the book is borrowed and when it must be returned．
May I renew my book? Our computer system does not allow us to renew books，so they must be returned and checked out again．We ask students to return their books at the beginning of the day with their bookmark／library card inside and sticking out．We will check the book in and put it aside for the student to get when he returns with his class．
How much is the fine if I return a book late? There are no fines for children in grades K-6．However students who have an overdue book may not borrow another book．
If I have the right to borrow two books and I have returned one，may I take out another book?
If the book you have left at home is not yet overdue，you may take out another book．However，if it is overdue，you will not be allowed to take out another book．
What happens if I lose a book?
If you lose a book，we will give you time to look for it．
Some good places to look for books：
On your bookshelf，but placed upside down or backwards
In another basket in the classroom
Under a bed
Under a sofa or chair or cushion
Behind the couch
In your locker or school bag
If you can't find the book，we will ask you to pay for it．Since it will probably cost more to replace the book than we originally paid，we will charge you the full replacement cost，including tax and other costs．
(1)
Jim is Grade Four，how many books he borrow a week?
A．Only one book．
B．Two books．
C．Three books．
D．Four books．
[ ]
(2)
What does the word“due”mean?
A．账单 B．预定的 C．到期的 D．因为
[ ]
(3)
Jim lost a library book and couldn't find it，what could he do?
A．He couldn't borrow any books anymore．
B．He must buy a new book．
C．He must pay for it．
D．He had to make a copy．
[ ]
(4)
If you return the book late，you will ______ ．
A．get a fine
B．pay for it
C．buy a book
D．not be able to borrow another book
[ ]
(5)
Which is right?
A．The school computer system can allow students to renew books．
B．Students can keep the books for a week．
C．If you lose a book，you have to buy a new book．
D．The book left home is overdue，but I can still borrow two books．
