The college entrance examination is just around the corner. Homework and tests will keep many of you up late at night, and you may plan to make up for your lost sleep during the weekends.     1     is it useful? A study published in the journal Current Biology completely has changed     2     people used to think. It shows that the habit of sleeping in on weekends doesn’t fix the damage done by a lack of sleep during the week. Even     3     (bad), it may damage your health.

When it comes to national parks, people often link them with those famous landmarks     1     (recommend) in tour and entertainment guides.

Recently, however, national parks in Canada appear on the prescriptions (处方) given by Canadian doctors.

According to CBC, a medical program named “PaRx”     2     (launch) in January by the government. Under the program, over 1,000 physicians, nurses and other medical     3     (professional) in Canada can prescribe the annual Adult Parks Canada Discovery Pass from the Canadian parks authority.     4     the pass, patients can gain free access to over 80 national parks, national historic sirs and national marine conservation areas around the country.

Many     5     (science) studies have shown that people     6     (spend) at least two hours a week in nature have     7     (good) health than before. It contributes to increasing life expectancy (预期寿命) and energy, reducing pain and stress, as well as improving heart health.

“We’re hoping that our PaRx program not only     8     (improve) patient health, but reduces costs to the healthcare system, and helps to grow     9     number of people who are more engaged in environmental activities,”said Prama Rahman,     10     is a leader of the BC Parks Foundation’s Healthy By Nature Program.

How can horses find their way back from a strange environment? For most people, that would be impossible without a map. Horses have a special system in their brains, and it works just     1     GPS. It shows signs for trees and other objects in their home areas. It also takes notes of new things in new areas.     2     horses keep their attention on those signs, they know which directions     3     (go). Who needs a self-driving car when you can have a horse? You’ll always get home safe and sound.

【推荐2】Styrofoam is plastic     1     a bad reputation.

It cannot be recycled without releasing (释放) dangerous pollutants into the air. The U. S. Environmental Protection Agency     2     (say) it is the fifth largest creator of dangerous waste.

Scientists from the U. S. and China have discovered that mealworms can digest plastic. One mealworm can digest a pill-sized amount of plastic a day.

Study co-author Wei-Min Wu says that in 24 hours, the plastic     3    (turn) into carbon dioxide.

Are the worms hurt by     4    (eat) plastic? The study found that worms eating Styrofoam were as     5     (health) as worms eating bran (糠).

Styrofoam is a lightweight material, about 95 percent air, with very good insulation properties (绝缘性), according to Earthsource.org. It is used in products from     6     (cup) that keep your drinks hot or cold to packaging materials     7     protect items during shipping.

“Solving     8     problem of plastic pollution is important. Landfill space is becoming limited,” says Wu, a Stanford University environmental engineering instructor.

About 33 million tons of plastic are thrown away in the United States every year. Plastic plates, cups and containers take     9     25 percent to 30 percent of space in America’s landfills. One Styrofoam cup takes more than 1 million years     10     (recycle) in a landfill, according to Cleveland State University.