题型:阅读理解 题类:模拟题 难易度:普通
上海市嘉定区2019届高三英语二模试卷(音频暂未更新)
Escaping predators (食肉动物), digestion and other animal activities—including those of humans—require oxygen. But that essential ingredient is no longer so easy for marine life to obtain, several new studies reveal.
In the past decade ocean oxygen levels have taken a dive—an alarming trend that is linked to climate change, says Andreas Oschlies, an oceanographer at the Helmholtz Center for Ocean Research in Germany, whose team tracks ocean oxygen levels worldwide. "We were surprised by the intensity of the changes we saw, how rapidly oxygen is going down in the ocean and how large the effects on marine ecosystems are," he says. It is no surprise to scientists that warming oceans are losing oxygen, but the scale of the drop calls for urgent attention. Oxygen levels in some tropical (热带的) regions have dropped by an astonishing 40 percent in the last 50 years, some recent studies reveal. Levels have dropped less significantly elsewhere, with an average loss of 2 percent globally.
A warming ocean loses oxygen for two reasons: First, the warmer a liquid becomes, the less gas it can hold. That is why carbonated drinks go flat faster when left in the sun. Second, as polar sea ice melts, it forms a layer of water above colder, more salty sea waters. This process creates a sort of lid that can keep currents from mixing surface water down to deeper depths. And because all oxygen enters the surface, less mixing means less of it at depth.
Ocean animals large and small, however, respond to even slight changes in oxygen by seeking refuge in higher oxygen zones or by adjusting behavior, Oschlies and others in his field have found. These adjustments can expose animals to new predators or force them into food-scarce regions. Climate change already poses serious problems for marine life, such as ocean acidification, but deoxygenation is the most pressing issue facing sea animals today, Oschlies says. After all, he says, "they all have to breathe."
Aside from food web problems, animals face various other physiological challenges as their bodies adjust to lower oxygen levels. Chinese shrimp (虾) move their tails less vigorously to preserve energy in lower oxygen environments. Some creatures, such as jellyfishes, are more tolerant of low oxygen than others are. But all animals will feel the impact of deoxygenation because they all have evolved their oxygen capacity for a reason, says Oschlies. "Any drop in oxygen is going to damage survivability and performance," he says.
Come and speak a week with us at Green and Gold Camp on the Sacramento Campus! Days are filled with scavenger hunts, river walks, the Challenge Center, water activities, arts and crafts, games and more! Your adventure begins at Sacramento State.
Awesome Activities:
Orienteering | Scavenger hunt |
Ropes course | Arts and crafts |
Cooking outdoors | Campus museums |
Fun in the sun | River walk |
Fun and educational games | Leave no trace principles |
Swimming |
Camps Dates and Details
Week 1: 6/1/2017-6/5/2017 | Week 2: 6/7/2017-6/11/2017 |
Week 2: 6/12/2017-6/16/2017 | Week 4: 6/19/2017-6/23/2017 |
Week 3: 6/26/2017-6/30/2017 | Week 6: 7/10/2017-7/14/2017 |
How much does this camp cost?
This camp is only $290 for an entire week of memories and friendships that will last a lifetime.
A minimum deposit of 50% per child, per camp is required for all registrations (non-refundable). Full payment is due 14 days prior to camp start.
When does the camp begin/end?
Drop-off for Green and Gold Camp begins each morning at 8:00 am. Camp activities begin at 8:30 each day and end at 5:00 pm. All children must be picked up no later than 5:00 pm. Late pick-ups will result in a $10 fee.
What does my child need to bring to the camp
Peak Adventures will provide a morning and afternoon snack, but your child needs to bring his/her own bag lunch every day. We also do water activities, so be sure to include a swim suit and a towel each day so they can participate. We suggest packing the following items each day:
T-shirt | Shorts | Sweatshirt |
Tennis shoes | Towel | Sunscreen |
Day pack | Water bottle | Lunch |
Sunglasses | Hat/Visor | Lip |
Swim-suit | Water shoes |
Camp must have a minimum of six campers for the program to run. No guarantees. You will receive a full refund for any cancelled camps.
CALL US AT 916-278-6321 FOR MORE INFORMATION AND TO RESERVE YOUR YOUTH CAMP SPOT TODAY.
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