1．    A team of scientists recently published one of the most comprehensive efforts yet to understand just how much carbon great whales absorb from the ocean，and the value that presents in the fight against climate change.
    "Whales are large-bodied animals，and they live for a long time.Many of them migrate over vast distances，" said study leader Heibi Pearson，a marine biologist at the University of Alaska Southeast. "And so they have the potential to have these huge impacts on the ecosystem，including the carbon cycle."
    In their most direct impact，whale bodies hold an enormous amount of carbon that would otherwise be in the ocean or atmosphere.Twelve great whale species hold an estimated 2 million tons of carbon in their bodies，the authors found.
    And that's just the living members of the whale family.Another 62，000 tons of carbon is kept under the sea every year in the form of whale falls.When a whale dies in open water and sinks into the deep，a lifetime of collected carbon goes with it.It can take up to 1，000 years for water and elements at the bottom of the sea to cycle back up to the surface，which means that carbon is effectively sequestered for that long.
    In addition，whales' waste facilitates the growth of organisms at the base of the marine food chain，promoting the growth of carbon-consuming life throughout the ecosystem.
    However，whale populations still haven't recovered from the destructive effects of industrial whaling.Commercial hunting in the 19th and 20th centuries decreased the total mass of whales on the planet by 81%，according to the authors.
    "Whales alone are not going to solve climate change，but thinking about whales as playing a role in the carbon cycle can help motivate whale conservation，" said Andrew Pershing，a co-author of the study. "There are a lot of win-wins there，and I think that's very true of a lot of natural climate solutions."

（1）How do whales influence the climate change？
A．By storing carbon in their bodies.
B．By speeding the carbon cycle.
C．By absorbing carbon from the air.
D．By consuming carbon on their migration.
（2）What does the underlined word "sequestered" in paragraph 4 probably mean？
A．Employed.
B．Trapped.
C．Monitored.
D．Measured.
（3）What can we learn about whales from the text？
A．Their population has risen by 81%.
B．Their waste contributes to the ecosystem.
C．Whale hunting has been banned altogether.
D．Their death will break the marine food chain.
（4）What is implied in Andrew Pershing's words？
A．We can rely on whales to change climate.
B．Whale protection still has a long way to go.
C．We'll soon win the battle against climate change.
D．Whale protection is beneficial to solving climate issues.

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．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.