Starting the day on an egg could keep your blood pressure (血压) under control, research suggests.
Scientists have shown that eggs produce proteins with a function similar to that of powerful blood
pressurelowering drugs.
      The researchers, from the University of Alberta in Canada, showed that when eggs come in contact
with stomach enzymes (酶) they produce a protein that acts in the same way as ACE inhibitors, drugs
taken by millions around the world to lower blood pressure.Fried eggs proved particularly effective, but
more work is needed to show the effects outside a lab and in the human body.
     Earlier this month, British researchers declared that, contrary to popular beliefs, it is healthy to go to
work on an egg.They concluded that the type of cholesterol (胆固醇) found in eggs has little effect on
increasing heart disease risks.
      Researcher Professor Bruce Griffin, from the University of Surrey, said, "The wrong beliefs linking
egg eating to high blood cholesterol and heart disease must be corrected.The amount of fat in our diet
has an effect on blood cholesterol that is several times greater than the relatively small amount of
cholesterol found in eggs.The UK public do not need to limit the number of eggs they eat.They can be
encouraged to include them in a healthy diet as they are one of nature's most nutritious foods."
     The British Heart Foundation dropped its threeeggaweek limit in 2005.However, almost half of
Britons believe the limit still applies.

1. From the text we know that ACE inhibitors are________.

A. a kind of medicine
B. a kind of protein
C. a kind of illness
D. a kind of food

2. According to what Professor Bruce said, eggs________.

A. are the most nutritious food
B. have no effect on blood cholesterol
C. can be included in a healthy diet
D. are forbidden to be eaten in the UK

3. We can infer from the text that________.

A. drugs to lower blood pressure will be replaced by eating eggs
B. stomach enzymes mixed with eggs can cure heart diseases
C. most Britons agree the threeeggaweek limit should be dropped
D. about 50% of Britons think eating an egg a day is bad for their health

4. The text is meant________.

A. to introduce scientific findings about eggs
B. to introduce a medicine made from eggs
C. to tell people how to lower their blood pressure
D. to advise people to eat as many eggs as possible

     There is no excuse for not doing your assignments(作业). If you can't come to school, you should
call your teacher or your classmate and ask about homework. It is your responsibility(责任)to find out
what homework you have missed. It is not the teacher's job to remind you of the missed assignments.
     You must not be absent on a test day. If you are seriously ill, call and let the teacher know you will
not be there for the test. If your teacher allows a make-up test(补考),you should take the test within one
or two days after you return to class. Serious illness is the only reason for missing a test.
     Be on time! It is impolite to be late. Also, it bothers other students. If you must come in late, be sure
to do it quietly. Have your books and papers out of your bag before you come into the room. Then go
to your seat and sit down quietly. In the USA, it is not necessary to knock before you enter the
classroom. Most teachers will give you a low grade if you are often late.
     In America, you should call your teacher by his or her last name instead of " teacher". Also you
should use Mr, Miss, Ms or Mrs before the last name ( such as Mrs Smith or Mr Jones). This is polite.
The teacher will tell you the title that he or she likes. It is impolite in the USA to eat, drink or chew gum
during class. Don't do these until the break. Also, removing your shoes in the classroom is not polite.

1. What should you do if you miss a class?

A. Give an excuse for missing the assignments.
B. Tell the teacher you can't come to school or do the assignments.
C. Ask your teacher to remind you of the missed assignments.
D. Call your teacher or your classmate to find out what assignments were given.

2. When can a student miss a test according to the passage?

A. When he / she is late for the test.
B. When he/ she is really sick.
C. When he / she failed another test.
D. When he / she doesn't want to have the test.

3. In America, if your teacher's name is Susan Black, what should you call her politely?

A. Ms Black      
B. Ms Susan      
C. Susan Black      
D. Teacher Black

4. Which of the following is NOT true according to the passage?

A. A student is thought to be impolite when he / she takes off his / her shoes in the classroom.
B. A student is thought to be impolite when he / she eats and drinks in class.
C. When a student is late for class, he / she must knock before he / she enters the classroom.
D. A student is thought to be impolite when he/she doesn't come for class on time.

     Fish have ears. Really. They're quite small and have no opening to the outside world carrying sound
through the body. For the past seven years, Simon Thorrold, a university professor, has been examining
fish ears, small round ear bones called otoliths.
   As fish grow, so do their otoliths. Each day, their otoliths gain a ring of calcium carbonate (碳酸钙).
By looking through a microscope (显微镜) and counting (数) these rings, Thorrold can determine the
exact age of a young fish. As a fish gets older, its otoliths no longer get daily rings. Instead, they get yearly
rings, which can also be counted, giving information about the fish's age, just like the growth rings of a
tree.
Ring counting is nothing new to fish scientists. But Thorrold has turned to a new direction. They're
examining the chemical elements (元素) of each otolith ring.
     The daily ring gives us the time, but chemistry tells us about the environment in which the fish swam on
any given day. These elements tell us about the chemistry of the water that the fish was in. It also says
something about water temperature, which determines how much of these elements will gather within
each otolith ring.
   Thorrold can tell, for example, if a fish spent time in the open ocean before entering the less salty water
of coastal areas. He can basically tell where fish are spending their time at any given stage of history.
   In the case of the Atlantic croaker, a popular saltwater food fish, Thorrold and his assistant have
successfully followed the travelling of young fish from mid-ocean to the coast, a journey of many
hundreds of miles.
   This is important to managers in the fish industry, who know nearly nothing about the whereabouts (行踪) of the young fish for most food fish in the ocean. Eager to learn about his technology, fish scientists
are now lending Thorrold their ears.

1. What can we learn about fish ears from the text? 

A. They are small soft rings.            
B. They are not seen from the outside. 
C. They are openings only on food fish.  
D. They are not used to receive sound.

2. Why does the writer compare the fish to trees? 

A. Trees gain a growth ring each day. 
B. Trees also have otoliths. 
C. Their growth rings are very small. 
D. They both have growth rings.

3. Why is it important to study the chemistry of otolith rings? 

A. The elements of the otoliths can tell the history of the sea. 
B. Chemical contents (含量) of otoliths can tell how fast fish can swim. 
C. We can know more about fish and their living environment. 
D. Scientists can know exactly how old a fish is.

4. How would you understand "fish scientists are now lending their ears"?

A. They are very interested in Thorrold's research findings.
B. They want to know where they can find fish.
C. They lend their fish for chemical studies.
D. They wonder if Thorrold can find growth rings from their ears.

     Have you ever wondered why birds sing? Maybe you thought that they were just happy. After all, you
probably sing or whistle when you are happy.
     Some scientists believe that birds do sing some of the time just because they are happy. However, they
sing most of the time for a very different reason. Their singing is actually a warning to other birds to stay
out of their territory.
     Do you know what a "territory" is? A territory is an area that an animal,usually the male, claims (声称)
as its own. Only he and his family are welcome there.No other families of the same species (物种) are
welcome. Your yard and house are your territory where only your family and friends are welcome. If a
stranger should enter your territory and threaten you,you might shout. Probably this would be enough to
frighten him away.
     If so, you have actually scared the stranger away without having to fight him. A bird does the same thing.
But he expects an outsider almost any time, especially at nesting (筑巢) season. So he is screaming all the
time,whether he can see an outsider or not. This screaming is what we call a bird's song,and it is usually
enough to keep an outsider away.
     Birds sing loudest in the spring when they are trying to attract a mate and warn others not to enter the
territory of theirs.
     You can see that birds have a language all their own. Most of it has to do with attracting mates and setting
up territories.

1. Some scientists believe that most of the time birds' singing is actually _____.

A. an expression of happiness
B. a way of warning
C. an expression of anger
D. a way of greeting 

2. What is a bird's "territory"?

A. A place where families of other species are not accepted.
B. A place where a bird may shout at the top of its voice.
C. An area for which birds fight against each other.
D. An area which a bird considers to be its own.

3. Why do birds keep on singing at nesting season?

A. Because they want to invite more friends.
B. Because their singing helps frighten outsiders away.
C. Because they want to find outsiders around.
D. Because their singing helps get rid of their fears.

4. How does the writer explain birds' singing?

A. By comparing birds with human beings.
B. By reporting experiment results.
C. By describing birds' daily life.
D. By telling a bird's story.

     A Brown University sleep researcher has some advice for people who run high schools : Don't start
classes so early in the morning. It may not be that the students who nod off at their desks are lazy. And
it may not be that their parents have failed to enforce (确保) bedtime. Instead, it may be that biologically
these sleepyhead students aren't used to the early hour.
     " Maybe these kids are being asked to rise at the wrong time for their bodies, " says Mary Carskadon,
a professor looking at problems of adolescent  (青春期的) sleep at Brown's School of Medicine.
     Carskadon is trying to understand more about the effects of early school time in adolescents. And , at
a more basic level, she and her team are trying to learn more about how the biological changes of
adolescence affect sleep needs and patterns.
     Carskadon says her work suggests that adolescents may need more sleep than they did at childhood ,
no less,as commonly thought.
     Sleep patterns change during adolescence, as any parent of an adolescent can prove. Most
adolescents prefer to stay up later at night and sleep later in the morning. But it's not just a matter of choice-their bodies are going through a change of sleep patterns.
     All of this makes the transfer from middle school to high school-which may start one hour earlier in
the morning-all the more difficult , Carskadon says. With their increased need for sleep and their
biological clocks set on the "sleep late , rise late"  pattern, adolescents are up against difficulties when it
comes to trying to be up by 5 0r 6 a. m. for a 7 : 30 a. m. first bell. A short sleep on a desktop may be
their bodies' way of saying,"l need a timeout. "

1. Carskadon suggests that high schools should not start classes so early in the morning because_______.

A. it is really tough for parents to enforce bedtime
B. it is biologically difficult for students to rise early
C. students work so late at night that they can't get up early
D. students are so lazy that they don't like to go to school early

2. The underlined phrase " nod off"  ( Paragraph l) most probably means"__________".

A. turn around                    
B. agree with others
C. fall asleep                      
D. refuse to work