1 . Eyesight plays a very important role in our daily life. Every waking moment, the eyes are working to see the world around us. Over forty percent of Americans worry about losing eyesight, but it's easy to include steps into our daily life to ensure healthy eyes. Here are five suggestions for a lifetime of healthy eyesight:
Schedule yearly exams.
Protect against UV rays .
Long-term stay in the sun creates risk to your eyes. No matter what the season is, it’s extremely important to wear sunglasses.
Two-thirds of Americans spend up to seven hours a day using computers or other digital products.
As part of a healthy diet, eat more fruits and vegetables each day. Vitamins C and E help protect eyesight and promote eye health.
Practice safe wear and care of contact lenses.
Many Americans use contact lenses to improve their eyesight. While some follow the medical guidance for wearing contact lenses, many are breaking the rules and putting their eyesight at risk.
Otherwise: you may have problems such as red eyes, pain in the eyes, or a more serious condition.
| A．Eat your greens. |
| B．Eye care should begin early in life. |
| C．They can properly protect your eyes. |
| D．Stay in good shape by taking more vitamins. |
| E．Parents usually don’t care about their own eyesight. |
| F．Always follow the doctor’s advice for appropriate wear. |
| G．This frequent eye activity increases the risk for eye tiredness. |
2 . Have you ever noticed that your fingertips are wrinkled (起皱的) when you’ve just finished swimming or washing dishes? It seems as if your hands have aged 30 years in a second. But is this an accident? Or is it something that nature has built into our bodies?
“If your finger’s wrinkling up had no use at all, it wouldn’t need to.” Professor Tom Smulders from Newcastle University UK told BBC News. By studying wet fingers closely, Smulders and his partners found that the wrinkles looked a bit like the patterns on the car tire or the bottom of the running shoes. So they made a guess that wrinkles on fingers might be able to help the hand hold things more tightly.
To test this, researchers asked 20 people to pick up marbles (大理石) from water with their hands. But before they started, some of the people had to keep their hands in water for half an hour. The researchers found that the people with wrinkled fingers completed the task faster than those with dry hands. But when they were asked to move dry marbles, all the people performed equally well no matter they had the wrinkled fingers or not. Researchers said our ancestors might not have played with marbles but wrinkled fingers could have made it easier for them to climb around in the wet forests and catch fish from rivers. Similarly, our toes also get wrinkled in water. This may have developed from our ancestors need to run on wet ground.
But the question is if wrinkled fingers are so helpful, why don’t our hands just stay that way all the time? Researchers explained that wrinkling had its disadvantage: wet fingertips are far less sensitive than smooth ones, reducing our sense of touch.
1. What does the underlined word “this” in the third paragraph refer to?| A．Whether fingers have wrinkles after they are put in water. |
| B．Whether wrinkled fingers can hold things more tightly. |
| C．Why keeping things in water makes them wrinkled. |
| D．Why wrinkles help hands hold things more tightly. |
| A．wrinkled hands hold dry things more tightly than dry hands do |
| B．dry hands hold dry things more tightly than wrinkled hands do |
| C．wrinkled hands hold wet things more tightly than dry hands do |
| D．dry hands hold wet things more tightly than wrinkled hands do |
| A．They are too sensitive to be touched. |
| B．They might be more likely to get hurt. |
| C．They cannot hold things tightly enough. |
| D．They are not so sensitive as dry fingers. |
3 . Crossing your legs is an extremely common habit; most people don't even notice that they're doing it when they sit down. While you may find it comfortable to sit with one knee crossed over the other, it might be causing health problems that you are not aware of.
A study published in Blood Pressure Monitoring stated that sitting with your legs crossed can increase your blood pressure. The reason for this is that the blood in your legs has to work against gravity to be pumped back to your heart and that crossing one leg over the other increases resistance(阻力), making it even harder for the blood to circulate. This causes your body to increase your blood pressure to push the blood back to the heart. You won't feel any immediate effects, but repeated, drawn-out increases in blood pressure can cause long-term health problems. So, planning to sit for a long period of time? Don't keep your legs crossed.
Crossing your legs at the knee can also cause pressure on the major nerve in your leg that passes just below your knee and along the outside of your leg, explains Richard Graves, a medical expert. This pressure can cause numbness and temporary paralysis (麻痹) of some of the muscles in your foot and leg, preventing you from being able to raise your ankle—what we know as that “pins and needles” sensation. While the feeling of discomfort may only last a minute or two, repeatedly crossing your legs until they feel numb can cause permanent nerve damage.
So next time you sit down, try to get yourself in the habit of sitting with both of your feet on the floor. Not only will it help your posture and stability, but it will also save your health in the long run.
1. What can we learn about crossing one's legs?| A．It is a very bad social habit. |
| B．It is usually practiced on purpose. |
| C．It can do harm to people's health. |
| D．It can make others feel uncomfortable. |
| A．affect your blood pressure |
| B．resist gravity effectively |
| C．lead to heart attacks easily |
| D．improve the function of legs |
| A．slight sharp pains |
| B．being a little nervous |
| C．serious muscle injuries |
| D．being highly flexible |
| A．To compare common habits. |
| B．To give readers some advice. |
| C．To evaluate effects of an experiment. |
| D．To introduce research methods. |
