1．Is Fresh Air Really Good for You？
We all grew up hearing people tell us to "go out and get some fresh air." （1）According to recent studies，the answer is a big YES，if the air quality in your camping area is good.
   （2）If the air you're breathing is clean—which it would be if you're away from the smog of cities—then the air is filled with life-giving，energizing oxygen.If you exercise out of doors，your body will learn to breathe more deeply，allowing even more oxygen to get to your muscles（肌肉）and your brain.
   Recently，people have begun studying the connection between the natural world and healing（治愈）.（3） In these places patients can go to be near nature during their recovery.It turns out that just looking at green，growing things can reduce stress，lower blood pressure，and put people into a better mood（情緒）.Greenery is good for us.Hospital patients who see tree branches out their window are likely to recover at a faster rate than patients who see buildings or sky instead.（4） It gives us a great feeling of peace.
   （5）While the sun's rays can age and harm our skin，they also give us beneficial Vitamin D.To make sure you get enough Vitamin D—but still protect your skin—put on sunscreen right as you head outside.It takes sunscreen about fifteen minutes to start working，and that's plenty of time for your skin to absorb a day's worth of Vitamin D.

A.Fresh air cleans our lungs.
B.So what are you waiting for？
C.Being in nature refreshes us.
D.Another side benefit of getting fresh air is sunlight.
E.But is fresh air really as good for you as your mother always said？
F.Just as importantly，we tend to associate air with health care.
G.All across the country，recovery centers have begun building Healing Gardens.

2．    Researchers following tiger sharks off the southern coast of Belize couldn't believe their eyes when they recently caught a different kind of fish.It turned out to be a Greenland shark，which is typically found in the Arctic and can live to be about 400 years old.
   The team of scientists thought the shark was dead when they finally pulled it to the surface.Unlike the tiger sharks they saw，this particular shark had black，worn-looking skin and pale blue eyes.Devanshi Kasana，a Ph.D．candidate at the Florida International University's Predator Ecology &；Conservation Lab，said the shark looked "really old".
   There was no doubt that the discovery was unexpected.Kasana said， "As soon as it entered our field of vision，we saw a black figure that was getting bigger and bigger.When it came to the surface，none of the crew with all of their combined fishing experience had seen anything like that." She said the discovery was especially exciting.She wondered how on earth these sharks，which were thought to mainly exist in the Arctic，could be found in the tropics as well.
   Greenland sharks can be several hundred years old.The reason for their long life may have something to do with their speed of growth，which is very slow.Greenland sharks grow approximately one-third of an inch per year and can grow to more than 20 feet in length.And researchers believe the sharks don't reach sexual maturity until sometime after the first 100 years of their life.
   According to Kasana，some scientists have theorized that the Greenland sharks can be found across the globe，if one knows where to look.They love cold water，which is why they're found in the Arctic.However，they've also been discovered as far south as off the coast of Georgia，thousands of feet beneath the ocean surface.
   The theory is that the closer the sharks are to the equator，the deeper researchers have to go to find them.And they go deep over 7，000 feet down，according to NOAA．

（1）What can we learn about the caught Greenland shark？
A．It is 400 years old.
B．It looks just like a tiger.
C．It has unique appearance.
D．It only lives near the Arctic.
（2）What does Kasana think of the discovery？
A．Doubtful and fearful.
B．Common and expected.
C．Exciting and threatening.
D．Surprising and confusing.
（3）What mainly contributes to Greenland sharks' long life？
A．The early maturity.
B．The mild environment.
C．The length of their bodies.
D．The slow pace of their development.
（4）What is the text mainly about？
A．The longest-living shark in the world.
B．The oldest fish living near the equator.
C．A Greenland shark appearing in Belize.
D．A theory about the long life of wild fish.

3．    Think of a monarch butterfly （帝王蝶），and a unique image pops up：black-and-orange wings，with some white spots around the black edges.Those white spots may actually help monarchs complete their long-distance migration by changing the airflow around their wings.This is the new idea of a team of researchers that has analyzed hundreds of monarch wings collected along their migration routes.
    "If you have larger white spots，you're simply more successful at reaching Mexico，" says Andy Davis，a researcher.He and his colleagues believe that the pattern of color could interact with sunlight to create some temperature differences on the wing that can change airflow，easing the butterflies' flight.
    Monarch butterflies definitely need to fly well to complete their annual fall migration of up to 3，000 miles.Monarchs from as far north as Canada fly south every fall all the way to some mountain top sites in central Mexico.Most research on butterfly coloring focuses on its use as a warning to predators （捕食者）.Since monarchs eat milkweed that contains poisons，their bright orange color serves as a signal that they're unpleasant prey （獵物）.
    Andy Davis had studied the black-and-white patterns on migrating birds，and concluded that black coloring could affect temperature and airflow in ways that might improve their flight performance.So the researchers decided to look at the black-and-white pattern in the edge of monarch wings.What they found is that the wings of the summer monarchs that aren't migrating have less white，while those that are migrating but haven't made it all the way to Mexico have more.And monarchs that successfully reached Mexico have even more white.
    "It is a totally new idea，" says Marcus Kronforst，a biologist. "I've worked on butterfly color patterns my whole life，but it's never crossed my mind that it might influence how the butterflies fly.I do think that this aerodynamic （空氣動(dòng)力學(xué)） explanation is exciting.It's definitely different.But I just think there are potentially some other explanations that could be explored."

（1）What is the new idea of monarch butterflies' white spots？
A．They serve as a warning to predators.
B．They improve butterflies' flying performance.
C．They attract the attention of butterflies' mates.
D．They help butterflies hide in their surroundings.
（2）How does Davis think white spots help monarch butterflies？
A．By changing the flow of air.
B．By making butterflies lighter.
C．By guiding migrating butterflies.
D．By turning sunshine into energy.
（3）What's Kronforst's attitude towards Davis new finding？
A．Unconcerned.
B．Supportive.
C．Skeptical.
D．Disappointed.
（4）What is the best title for the text？
A．Monarch butterflies migrate the longest distance
B．Monarch butterflies use airflow to help their flights
C．Monarch butterflies have more white spots than others
D．Monarch butterflies' white spots may help them fly farther