The sudden second child is what makes the today's younger generation feel exhausted.（)

A．Many？extracellular？signals？acting？via？GPCRs？affect？the？activity？of？the？enzyme？adenylyl？cyclase？and？thus？alter？the？intracellular？concentration？of？the？second？messenger？molecule？cyclic？AMP.

B．Most？commonly,？the？activated？G？protein？α？subunit？switches？on？the？adenylyl？cyclase,？causing？a？dramatic？and？sudden？increase？in？the？synthesis？of？cyclic？AMP？from？ATP.

C．To？help？terminate？the？signal,？a？second？enzyme,？called？cyclic？AMP？phosphodiesterase,？rapidly？converts？cyclic？AMP？to？ordinary？AMP.？Cyclic AMP phosphodiesterase is continuously active inside the cell. Because it eliminates cyclic AMP so quickly, the cytosolic concentration of this second messenger can change rapidly in response to extracellular signals, rising or falling tenfold in a matter of seconds.

D．Cyclic AMP is water-soluble,so it can, in some cases, carry the signal throughout the cell, traveling from the site on the membrane where it is synthesized to interact with proteins located in the cytosol, in the nucleus, or on other organelles. One？way？that？caffeine？acts？as？a？stimulant？is？by？inhibiting？this？phosphodiesterase？in？the？nervous？system,？blocking？cyclic？AMP？degradation？and？thereby？keeping？the？concentration？of？this？second？messenger？high.

of high-speed Web. For decades, Americans have anxiously (1)_____ each war through a new communications (2)_____, from the early silent film of World War I to the 24-hour cable news (3)_____ of the first Persian Gulf War.

Now, (4)_____ bombs exploding in Baghdad, a sudden increase in wartime (5)_____ for online news has become a central test of the (6)_____ of high-speed Internet connections. It is also a good (7)_____ both to attract users to online media (8)_____ and to persuade them to pay for the material they find there, (9)_____ the value of the Cable News Network persuaded millions to (10)_____ to cable during the last war in Iraq.

(11)_____ by a steady rise over the last 18 months in the number of people with high-speed Internet (12)_____, now at more than 70 million in the United States, the Web sites of many of the major news organizations have (13)_____ assembled a novel collage(拼贴) of (14)_____ video, audio reports, photography collections, animated weaponry (15)_____, interactive maps and other new digital reportage.

These Internet services are (16)_____ on the remarkable abundance of sounds and images (17)_____ from video cameras (18)_____ on Baghdad and journalists traveling with troops. And they have found a (19)_____ audience of American office workers (20)_____ their computers during the early combat.

A．notified

B．publicized

C．followed

D．pursued

animals to have teeth were fish. These sea creatures lived millions of years ago. They had many finely pointed teeth for grabbing food from the water. They were distant cousins of today’s sharks.The teeth of animals help them do certain jobs or eat certain kinds of foods. Elephants have two large teeth, called tusks, which they use for digging up plants or for fighting. Lions and tigers have long, sharp teeth for tearing apart other animals. Those of horses and cows are short and flat. They are used for grinding plants.People have three main kinds of teeth. They have teeth that cut, teeth that tear, and teeth that grind. When biting into a piece of fruit, people use their cutting teeth. When pulling a piece of meat from a bone, they use their tearing teeth. When nibbling on a fresh carrot, they use their grinding teeth.Every person grows two sets of teeth. The first set often begins to appear when a baby is about six months old. It lasts until the child is about six years old. Then the baby teeth fall out and the second teeth come in. This second set must last for the rest of a person’s life.It is important for people to take care of their teeth. They must eat the right foods. They should brush their teeth properly. Teeth should be checked twice a year by a dentist.

1.Fish have many () teeth for () food.

A.noticeable, catching

B.visible, grasping

C.sharp, snatching

D.fine, catching

2.Which of the following statements about teeth is true？()

A.Elephants have three large tusks

B.Teeth of horses and cows are short and sharp

C.The first set of teeth of a person often begins to appear when he is about six years

D.Sea creatures were the first animals having teeth

3.The word “nibble” in the third paragraph bears the meaning of ().

A.eating with small repeated bits

B.showing slight interest in something

C.taking hold of with a sudden rough movement

D.crushing into small pieces or into powder

4.From this passage we can draw a conclusion that ().

A.all the teeth have the same function

B.animals don’t try to protect their teeth

C.teeth are important both for human and animals

D.we should care our teeth and often have them checked

5.It is a piece of writing about ().

A.botany

B.animals

C.popular science

D.dentistry

dles for injection, you nameit. But few people think of the wonder a needle works in the hands of those who practice acupuncture.

During the past ten years of so, I have been suffering from a terrible headache. It seems to be getting from bad to worsethese days. Last night I got a sudden pain in my head. It was so terrible that I could hardly bear it. Although I swallowed all kinds of pain-killers, I didn't feel any better. It seemed that there was nothing I could do but phone for a doctor.

One of our neighbors happened to be with us. He was not a doctor, but he timidly offered his help, saying "Do you mind if I tried acupuncture on you？ These needles may possibly do you some good."I agreed. In a moment, he had taken out a few needles from his purse. Without a moment's delay, he fixed a few needles into the skin on my head here and there. Before long, I felt thoroughly relieved.

Just then, the doctor sped through my house and said,"Where is our patient？"

"Sorry, Doctor, You are too late. It's killed!" I answered in delight.

It's a miracle, isn't it？

1)、The word ''name'' in the first paragraph means to give a name to the needles.

A.T

B.F

2)、The underlined phrase “from bad to worse”in the second paragraph refers to the state of the man's health.

A.T

B.F

3)、According to the passage，soon after the acupuncture, the man was completely recovered.

A.T

B.F

4)、"You are too late. It's killed." means that the pain was killed because the doctor came late.

A.T

B.F

5)、The passage tells us that the effect of acupuncture on the patient was unbelievable.

A.T

B.F

up Broadway.Nora noticed a guy sitting inside a cardboard box next to a newsstand.She pulled at my coat sleeve and said, “That man's cold, Daddy.Can we take him home？”

I don't remember my reply, but I do remember a sudden heavy feeling inside me.I had always been delighted at how much my daughter noticed in her world, whether it was birds in flight or children playing.But now she was noticing suffering and poverty.She wasn't even four.

A few days later, I saw an article in the newspaper about volunteers who delivered meals to elderly people.The volunteers went to a nearby school on a Sunday morning, picked up a food package, and delivered it to an elderly person.I signed us up.Nora was excited about it.She could understand the importance of food, so she could easily see how valuable our job was.When Sunday came, we picked up the package and phoned the elderly person we'd been assigned.She invited us right over.

The building was depressing.When the door opened, facing us was a silver-haired woman in an old dress.She took the package and asked if we would like to come in.Nora ran inside.I reluctantly followed.Our hostess showed us some photos of her family.Nora played and laughed.I accepted a second cup of tea.When it came time to say good-bye, we three stood in the doorway and hugged.I walked home in tears.

Where else but as volunteers do you have the opportunity to do something enjoyable that's good for yourself as well as for others？ Indeed, the poverty my daughter and I helped lessen that Sunday afternoon was not the woman's alone — it was in our lives, too.Now Nora and I regularly serve meals to needy people and collect clothes for the homeless.Yet, as I've watched her grow over these past four years, I still wonder — which of us has benefited more？

26.The man Nora noticed on that evening was probably ______.

A.asking for food

B.one of those homeless

C.taken home by the author

D.buying a newspaper

27.The author had a sudden heavy feeling (Para.2), because ______.

A.his daughter had noticed the dark side of life

B.he did not want to take the guy home

C.he felt a deep sympathy for the guy

D.his daughter was afraid of what she saw

28.Their volunteer job was to ______.

A.visit poor homes

B.serve meals at a nearby school

C.pick up packages for poor, elderly people

D.deliver food to needy, elderly people

29.The word “us” in the last paragraph refers to ______ .

A.the author and the old woman

B.the giver and receiver of the help

C.the author and his daughter

D.the author and the guy in the box

30.The best title for this passage might be “______.”

A.A Loving Kid

B.A Lesson in Caring

C.Volunteers at Work

D.How to Help the Needy

conservative means being opposed to great or sudden change.()

冠状动脉性猝死(sudden coronary death)(名词解释)

A.sugar

B. sudden

C. surprise

D. Saturday

It ______ came to her that she had been wrong all the time. (sudden)