What does fizz (氣泡) taste like? In Bubbly (多泡的)drinks such as sodas, tiny bubbles give the drink a lift--- and have a distinct taste, In a new study on mice, scientists have connected that fizzy-taste feeling to the ability to taste sourness, such as that of oranges or vinegar.
Scientists first thought the taste of bubbles came from the bubbles bursting on the tongue, but now ate starting to think differently. Charles Zuker, of Columbia University, and his team studied the nervous system of mice to understand how the tongue tastes carbon dioxide, which is the gas that makes up the bubbles.
Animals, including human beings, are able to detect different tastes by using taste buds(味蕾) which pick up tastes in the mouth, and then send them to the brain. In the experiment, different groups of mice were genetically engineered to be missing one of the senses involved in taste. “Genetically engineered” means the researchers were able to turn off the switches for certain senses by changing the genes responsible for taste. The mice in one group could not taste sweet; another, sour; the third, bitter, and the fourth, salt. When the scientists gave carbon dioxide to the mice, the nervous systems of all the mice responded to the gas, except those of the mice that could not taste sour.
This shows that the taste of the bubbles must be sour, and that by turning off the ability of the mice to taste sour, the scientists also turned off their ability to taste carbon dioxide. When they studied the cells that detect sourness, the researchers found a protein attached to the cells that is important to the process of tasting carbon dioxide. When carbon dioxide comes into contact with this protein, the protein knocks off particles called protons. These protons(質(zhì)子), in turn, travel to the brain, which says ,” Hey! That’s a taste!”
It may seem like a lot of work to get from a can of soda to a taste, but the science of the senses is anything but simple, “ Taste is a challenging system to study,” one researcher says.
What is the most important function of the bubbles?
A. To look interesting . B. To make drinks taste good.
C. To make drinks funny. D. To produce a lot of fizz.
From the experiment the researchers learned that______.
A. sourness has nothing to do with the taste of bubbles.
B. there is a connection between sourness and bubbles.
C. the taste of bubbles is better if it’s less sour.
D. most mice cannot taste carbon dioxide.
It can be inferred from the passage that ________.
A. the taste of bubbles is produced by the bubbles bursting on the tongue.
B. the nervous systems of mice show how the tongue tastes carbon dioxide.
C. taste seems simple but is very complex to research.
D. nerve cells sending signals to the brain is the first step in tasting something.
Which of the following would be the best title for the passage?
A. Nervous Systems Understand How the Tongue Tastes.
B. The Process of Taste
C. The taste of Bubbles.
D. Different Animals Detect Different Tastes.
科目:高中英語 來源: 題型:閱讀理解
A morning rarely began so perfect. I took in the fresh air and felt my heart run into an enthusiastic rhythm. Though cool, the sun warmed my back as it rose over the horse from not far from my house. The slightest wind danced on my skin. Just enough to keep a runner form overheating. My ever-faithful jogging partner, a black dog named Nika pulled my leg with her mouth, mirroring my eagerness to start our run.
We raced forward with determination, ready to leap tall buildings and race against speeding trains. We pushed harder and ran faster, demonstration our skill and impressing passing motorists and neighbors.
We kept on running until we hit the Beast, a name for a very difficult, nearly two-mile long steep climb.
Only a few paces into the Beast, I gasped for air. Far short of superhero status, my enthusiasm and active steps were lost somewhere at the base of the hill. A vision of the newspaper and a cup of coffee waiting in my kitchen appeared, attracting me to turn back toward home.
With a glance I noticed Nika wasn’t doing any better. She continued to faithfully follow me, putting one paw in front of the other, but without her former eagerness. Her tiredness touched me. And in that moment, I felt a sudden spark of renewed determination to press on. I couldn’t allow this mountain to get the better of us. To improve both our spirits, I managed to shout, “Good girl, Nika! Keep going…you can do it!”
“I’m encouraging a dog, for heaven’s sake!’’ I needed to pull myself together. With a few simple words, I changed our course. One moment we were on the edge of quitting. The next, our feet picked up the pace and we continued. Though tired and discouraged myself, with a few kind words I impacted a dog’s ability to go further. I’m sure I could have completed the opposite with ill-chosen comments and an unpleasant tone. Instead, the Beast was defeated and we flew like heroes the rest of the way home.
Life is full of beasts to conquer. For some, it is the seemingly impossible climb of cancer. For others, their beast takes the shape of parenting a child or a teenager. Uphill climbs come in all shapes and sizes, common only in their ability to defeat, discourage and tempt tired travelers to quit. Sometimes all that’s needed is a few spoken, well-timed words of encouragement from a fellow runner – someone who sees the struggle, dares to jogs alongside, and cares enough to say, “Keep going! You can do it! You’re not alone. I believe in you!”
The writer starts the text by describing________.
A. the beautiful scene of the morning
B. his or her preparations for a jogging
C. a lively dog named Nika
D. the growth of crops at the farm
The writer mentioned the newspaper and coffee to suggest that he or she _______.
A. liked reading newspapers while drinking coffee
B. had an intention to give up running
C. would treat himself or herself to coffee after running
D. might appear on the newspaper for the long running
The writer decided to continue running _______.
A. after he or she found the dog was still energetic
B. because they came near the top of the hill
C. when he or she noticed the tired dog
D. before they arrived at the bottom of the hill
What does the writer expect to show by telling the story?
A. Words are powerful than deeds.
B. Beasts in life aren’t easily to conquer.
C. Dogs are the best friend of humans.
D. Try it one more time before giving up.
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科目:高中英語 來源: 題型:
—What does the sign over there read?
—“No person ___ smoke or carry a lighted cigarette,cigar or pipe in this area.”
A.will B.may
C.shall D.must
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科目:高中英語 來源: 題型:閱讀理解
Winter depression (or winter blues) is a common affliction (折磨) for those who live in our northern climate. Its clinical name is seasonal affective disorder (or SAD) and up to 5% of the population (especially in northern states) may suffer from it. Seasonal affective disorder is characterized by feelings of sadness and depression that occur in the winter months when the temperatures drop and the days grow short . The depression is often associated with excessive eating or sleeping and weight gain. Women are twice to three times more likely to suffer from the winter blues than men.
There are many effective treatments for winter depression, some of which you can do to help yourself. Increasing your daily exposure to as much natural light as possible can be helpful to many. Any time that you have the opportunity to gain access to more sunlight in the winter months, you should try to do so. Taking walks throughout the day (even if you don’t normally do so), sitting next to a south-facing window at your office, in a classroom, or at home will increase your sunlight exposure. Exercising next to a window or outdoors (when possible) is another activity that can help.
Although it may be difficult to do, maintaining your schedule and lifestyle will help to keep the depression at bay. A regular pattern of sleep is the most important thing to maintain. It may be helpful, for instance, to have your bedroom lights on a timer to turn on a half-hour before you wake. This may help in waking at a regular time every morning, when it is still dark outside in the winter months.
Light therapy has shown to be an effective treatment for seasonal affective disorder. While you can purchase expensive, specialized light therapy lighting fixtures for your home or office, some inexpensive alternatives are also available. Another lighting technique to try is to replace commonly used light bulbs in your home with brighter full spectrum (also known as broad spectrum) light bulbs. While more expensive than regular light bulbs, these bulbs provide light that is similar to natural sunlight.
If none of these techniques seem to help your depressive symptoms, you should consider consulting your family physician or a mental health professional. The winter blues are a form of depression and can be readily treated w ith medications or psychotherapy when other self-help methods aren’t effective. Don’t be afraid to talk about this condition with a professional; it’s nothing to be ashamed or afraid of. With a little effort, the winter blues can be beaten
What do we know about winter depression?
A. It is very common where the weather is cold.
B. It may lead to weight gain.
C. It occurs when the temperatures drop.
D. It seldom affects men.
What is the most important factor in the therapy introduced in the second paragraph?
A. Exposure to natural light.
B. Sports in winter months.
C. Outdoor activities.
D. Sunlight through the window.
What does “to keep the depression at bay” mean in the third paragraph?
A. To shorten the duration of the depression.
B. To use light to resist the depression.
C. To keep the depression manageable and minimal.
D. To delay the occurrence of the depression.
For winter depression, light therapy ___________.
A. is much more effective than other kinds of therapy
B. is so expensive that some may not be able to afford it
C. encourages people to do outdoor exercises
D. needs specialized bulbs to replace ordinary ones
We can infer from the passage that __________.
A. self-help methods do not work 100% of the time
B. medications or psychotherapy is much more effective
C. mental health professionals don’t recommend self- help methods
D. most people prefer self-help methods to medications
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科目:高中英語 來源: 題型:
—What does Roger Brown do for a living?
—He is one of the most successful________ in the city.
A.newspaper reporter B.newspaper’s reporters
C.newspaper’s reporter D.newspaper reporters
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科目:高中英語 來源: 題型:閱讀理解
How to Be a Winner
Sir Steven Redgrave
Winner of 5 Olympic Gold Medals
“In 1997 I was found to have developed diabetes (糖尿病) .Believing my career (職業(yè)生涯)was over, I felt extremely low.Then one of the specialists said there was no reason why I should stop training and competing.That was it----the encouragement I needed.I could still be a winner if I believed in myself.I am not saying that it isn’t difficult sometimes.But I wanted to prove to myself that I wasn’t finished yet.Nothing is to stand in my way.”
Karen Pickering
Swimming World Champion
“I swim 4 hours a day, 6 days a week.I manage that sort of workload by putting it on top of my diary.This is the key to success—you can’t follow a career in any field without being well-organized.List what you believe you can achieve.“Trust yourself, write down your goals for the day, however small they are, and you’ll be a step closer to achieving them.”
Kirsten Best
Poet & Writer
“When things are getting hard, a voice inside my head tells me that I can’t achieve something.Then, there are other distractions, such as family or hobbies.The key is to concentrate.When I feel tense, it helps a lot to repeat words such as ‘calm’, ‘peace’ or ‘focus’, either out loud or silently in my mind.It makes me feel more in control and increases my confidence.This is a habit that can become second nature quite easily and is a powerful psychological (心理的) tool.”
What does Sir Steven Redgrave mainly talk about?
A.Difficulties influenced his career.
B.Specialists offered him medical advice.
C.Training helped him defeat his disease.
D.He overcame the shadow of illness to win.
What does Karen Pickering put on top of her diary?
A.Her training schedule. B.Her daily happenings.
C.Her achievements. D.Her sports career.
What does the underlined word “distractions” probably refer to?
A.Ways that help one to focus.
B.Words that help one to feel less tense.
C.Activities that turn one’s attention away.
D.Habits that make it hard for one to relax.
According to the passage, what do the three people have in common?
A.Courage. B.Devotion. C.Hard work. D.Self-confidence.
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