单选题Until about a century ago, the deep ocean floor, was completely inaccessible, hidden beneath waters averaging 3,600 meters deep.A understandableB recognizable C unreachable D unusable

Below 600 feet ocean waters range from dimly lit to completely dark.

A:inadequately
B:hardly
C:faintly
D:sufficiently

共用题干
第二篇

Explorer of the Extreme Deep

Oceans cover more than two-thirds of our planet.Yet,just a small fraction of the underwater world has been explored.Now,Scientists at the Woods Hole Oceanographic Institution(WHOI)in Massachusetts are building an underwater vehicle that will carry explorers as deep as 6,500 meters (21,325.5 feet).The new machine,known as a manned submersible or human-operated vehicle (HOV),will replace another one named Alvin which has an amazing record of discovery,playing a key role in various important and famous undersea expeditions.Alvin has been operating for 40 years but can go down only 4,500 meters(14,763.8 feet).It's about time for an upgrade,WHOI researchers say.
Alvin was launched in 1964.Since then,Alvin has worked between 200 and 250 days a year, says Daniel Fornari,a marine geologist and director of the Deep Ocean Exploration Institute at WHOI.During its lifetime,Alvin has carried some 12,000 people on a total of more than 3,000 dives.A newer,better versions of Alvin is bound to reveal even more surprises about a world that is still full of mysteries,Fornari says.It might also make the job of exploration a little easier."We take so much for granted on land."Fornari says."We can walk around and see with our eyes how big things are.We can see colors,special arrangements."
Size-wise,the new HOV will be similar to Alvin.It'll be about 37 feet long. The setting area inside will be a small sphere,about 8 feet wide,like Alvin.It'll carry a pilot and two passengers.It will be just as maneuverable.In most other ways,it will give passengers more opportunities to enjoy the view,for one thing. Alvin has only three windows,the new vehicle will have five,with more overlap so that the passengers and the pilot can see the same thing.
Alvin can go up and down at a rate of 30 meters every second,and its maximum speed is 2 knots(about 2.3 miles per hour),while the new vehicle will be able to ascend and descend at 44 meters per second.It'll reach speeds of 3 knots,or 3.5 miles per hour.

Which of the following statements is NOT a fact about Alvin?
A:It can carry explorers as deep as 6,500 meters.
B:It has played a key role in various important undersea expeditions.
C:It was launched in the sixties of the twentieth century.
D:It has been used for more than 40 years.

Below 600 feet ocean waters range from faintly lit to completely dark.

A:inadequately
B:hardly
C:dimly
D:sufficiently

Text 4 Turning oil rigs into reefs saves money and marine life.Yet many greens oppose it.When an offshore well stops producing oil,what should be done with the rig?One option is to haul it ashore,break it up and recycle it.This is expensive.For a big,deep-water oil or gas platform,it can cost S200m.Just hiring a derrick barge massive enough to do the job can cost$700,000 a day.But there is an altemative:simply leave most of the structure where it is.That is what you would expect a greedy oil firm to do:despoil the ocean just to save a lousy few million dollars.The surprise is,the cheap option may actually be greener.More than 490 platforms in American waters have become reefs in the past three decades.The federal Bureau of Safety and Environmental Enforcement urges states to issue reefing permits.State coffers gain:oil firms typically hand over half the money they save by reefing.Those savings vary greatly.Small platforms in shallow waters can often be removed for$lOm,but sometimes for as little as$lm,according to DecomWorld,a consultancy.But for states with lots of offshore oil rigs,the windfalls soon add up.Mississippi pocketed an average of$625,000 for each of the 12 permits it has issued,according to Melissa Scallan of the state's Department of Marine Resources.Louisiana's take has averaged$270,000 per reefing-and the state has seen 336 0f them,says Mike McDonough of the Louisiana Department of Wildlife and Fisheries.Far bigger savings arc possible in the deep waters off California.Four years ago the Golden State passed a law allowing reefing.Operators are Ioth to estimate costs publicly,but the Tulane University Energy Institute reckons that reefing the state's 27 platforms could save$2 billion.A platform or two could be retired as early as next year,though rising oil prices may mean they keep pumping longer.The debate is likely to intensify.In the Gulf of Mexico some 400 platforms are now being decommissioned each year.Divers and many fishermen want more to be reefed;shrimpers complain that reefs prevent them from dragging nets across parts of the ocean floor.In Califomia operators must decide quickly if they wish to turn redundant rigs into reefs.Until 2017 firms can keep 45%of the savings.After that the figure falls t0 35%until 2023;then it drops to just 20%.For now,the evidence suggests that reefing is a rare policy.It is both eco-friendly and pays for itself.
It can be inferred from the text that will save least from rectifying_____

A.the state authority
B.shoal waters
C.deep waters
D.gold coast