The findings could lead to a better understanding of what is the immediate cause of heart attacks, according to Dr Stefan Willich of the Free University. “We know a lot about long-term risk factors such as smoking and cholesterol(胆固醇)but we don’t know what actually causes heart attacks, so we can’t give clear advice on how to prevent them,” he said.
Monday mornings have a double helping of stress for the working body as it makes a rapid change from sleep to activity, and from the relaxing weekend to the pressures of work.
“When people get up, their blood pressure and heart rate go up and there are hormonal(内分泌)changes in their bodies,” Willich explained. “All these things can have an unfavourable effect in the blood system and increase the risk of a clot(血凝块)in the arteries(动脉)which will cause a heart attack.”
“When people return to work after a weekend off, the pace of their life changes. They have a higher workload, more stress, more anger and more physical activity,” said Willich.
59.Monday morning feeling, as this passage shows, .
A. is not so serious as people thought
B. is harmful to working people in developed countries.
C. is the first killer in Germany and Italy.
D. is created by researchers in Germany and Italy
60.To protect people from suffering from heart attack, doctors have paid much attention to . A. people’s working time B. people’s living place
C. people’s diet and lifestyle D. people’s nationalities
61.It can be learned from this passage that heart attack has nothing to do with .
A. blood pressure B. heart rate C. hormonal changes D. blood group
62.If the researchers give us some advice to avoid Monday morning feeling, what might it be?
A. Stop working on Monday B. Create a pleasant working environment
C. Get up late on Monday morning D. Go to work with a doctor
D
The huge Florida wetland known as the Everglades is a slow-moving river 80 kilometres wide but only a few centimeters deep. People call the Everglades a “river of grass” because sawgrass covers most of it. Sawgrass is not really grass. It is a plant that has leaves edged with tiny sharp teeth that can easily cut through clothes—and skin!
Travel in the Everglades is difficult. You cannot walk through shallow water because the sawgrass will cut you. The water is too shallow for regular boats. So, we use an airboat. An airboat is a flat, open boat. Like an airplane, it has a big propeller to move it. The propeller is fixed on the rear of the boat. It makes a tremendous noise, but it does the job. The boat skims along the water’s surface. Although we can still get lost in an airboat, at least we are above the alligators(短吻鳄).
While hundreds of different kinds of animals live in the Everglades, the most famous is surely the alligator. Once endangered, alligators are now protected within Everglades National Park. Visitors are likely to see them both on land and in water.
For a long time, dangers have threatened the Everglades. Around 1900, some people felt this precious wetland should be drained (排干). They said it was just a big swamp and not good for anything. In the 1920s, there was a land boom in Florida. People wanted to build homes everywhere, including in the Everglades. They built canals, levees (防洪堤), and other water systems that stopped the rivers flowing into the Everglades. Factories were built near rivers that flowed into the wetland. These factories dumped poisonous waste that damaged the Everglades ecosystem.
People are now working to preserve the Everglades National Park for the future. Right now, one big problem is the paperbark tree. This tree is an invader from Australia.
Paperbark trees soak up a lot of water. In the early 1900s, people brought them to Florida because they thought they would help drain the Everglades. However, the invaders adapted too well. Paperbark trees have taken over hundreds of thousands of acres of the Everglades and killed other trees. Scientists are cutting down these invaders or spraying them with herbicides (除草剂) to kill them.
63. Which helps to explain why it is difficult to travel in Everglades?
A. Airboats may make a very big noise.
B. You may get lost when passing through.
C. Paperbark trees soak up too much water there.
D. Many different kinds of animals are to be protected.
64. Why do people use airboats instead of normal boats?
A. They have big propellers to move them faster than alligators.
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