Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 3 to 7.
Polar bears are in danger of dying out. Unlike some other endangered animals, it's not hunters that are the problem, it's climate change. Since 1979, the ice cap at the Arctic Circle where the polar bears has reduced in size (3)_________ about 30 per cent. The temperature in the Arctic has slowly been rising and this is (4)_________ the sea ice to melt, endangering the polar bears' home. The polar bears' main sources of food are the different types of seals found in the Arctic. They catch them by waiting next to the air holes seals have made in the ice. (5)_________ the bears are very strong swimmers, they could never catch seals in water. This means that the bears really do rely on the ice to hunt.
Polar bears also need sea ice to travel. They can cover a huge territory and often swim from one part of the ice to another. They have been (6)_________ to swim up to 100 km, but when there is less ice, they may have to swim further and this can (7)_________ fatal to the bears. A number of bears have drown in the last few years and scientists believe that it is because they were not able to reach more ice before they became too tired and couldn't swim any further.
(3)________




A.in
B.by
C.within
D.for

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Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.
The United Nations recently outlined the extent of the global water crisis, saying that 2.7 billion people would face severe water shortages by 2025 if consumption continues at current rates. Today, an estimated 1.2 billion people drink unclean water, and about 2.5 billion lack proper toilets or waste disposal systems. More than five million people die each year from diseases related to unclean water. Humans are pumping water out of the ground faster than it can be replenished. In this difficult situation, a water conservationist, Neil MacLeod in South Africa, has found innovative ways to improve his local water situation.
Neil MacLeod took over as head of Durban Metro Water Services in 1992. The situation he found was a catastrophe. Durban had one million people living in the city and another 1.5 million people who lived in poverty just outside it. The entire city was rife with broken water pipes, leaky toilets, and faulty plumbing whereby 42 percent of the region's water was simply being wasted.
MacLeod's crews began repairing and replacing water pipes. They put water meters on residences, replaced eight-liter toilets with four-liter models, and changed wasteful showers and water taps. To ensure that the poor would receive a basic supply of water, MacLeod installed tanks in homes and apartments to provide 190 liters of water a day free to each household. Water consumption in Durban is now less than it was in 1996, even as 800,000 more people have received service. Through sensible water use, Durban's conservation measures paid for themselves within a year. No new reservoirs will be needed in the coming decades, despite the expected addition of about 300,000 inhabitants.
MacLeod has also turned to water recycling. At the water recycling plant, wastewater is turned into clean water in just 12 hours. Most people are unable to discern a difference between the usual city drinking water and the treated wastewater, although it is actually intended for industrial purposes.
Some people still hope that new technology, such as the desalination of seawater, will solve the world's water problems. "But the fact is, water conservation is where the big gains are to be made," says Sandra Postel of the Global Water Policy Project. The dedication and resourcefulness of people like Neil MacLeod offer inspiration for implementing timely and lasting solutions to the world's water concern.
(Adopted from “Reading Explorer 4” by Paul MacIntyre and David Bohlke)
The word "catastrophe" in paragraph 2 is mostly a situation which is .




A.local
B.disastrous
C.familiar
D.unlikely