Most foods that we consume on a daily basis like potatoes and rice are loaded withcarbohydrates. Contrary to popular belief, carbohydrates have many health benefitssome fight diseases such as high blood pressure and heart disease, and others help toprevent cancer and stroke. Cutting these foods out of your diet may deprive your bodyof the many health benefits of carbohydrates.
One of the best benefits of carbohydrates is their ability to help to maintain the health of our organs, tissues, and cells. Scientific studies have shown that one type of carbohydrate called fiber reduces the risk of heart disease. Carbohydrates also contain
antioxidants (抗氧化剂) , which protect the body's cells from harmful particles with thepotential to cause cancer.
This does not mean that the human body can survive on a diet composed entirely ofcarbohydrates. We also need certain percentages of proteins and fats to maintain healthybodies. But carbohydrates certainly should not be avoided altogether. In fact, the foodpyramid, the recommended basis of a healthy diet, shows that a person should consumesix to eleven servings of breads and grains, as well as three to four servings each offruits and vegetables - all carbohydrate-containing foods. It is easy to see why cuttingcarbohydrates out of a person's diet is not a good idea.
The only way to know what is truly healthy for your own body is to talk to a nutritionist or dietician, who can help you choose foods that are right for you as well asguide you toward a proper exercise program forweight loss, or muscle gain. Theseprofessionals will never tell you to cut out carbohydrates entirely! The bottom line:listen to the experts, not the advertisers!
86. As is used in Paragraph l, the word "exhausted" most possibly means______
A. derived   B. deprived
C. startled  D. starving
87. According to the author, advertisers who sell “carb-free” products_______
A. offer healthy options  B. are responsible for obesity
C. are not telling the truth  D. value consumers' well-being
88. Which of the following is NOT one of the health benefits of carbohydrates?
A. Prevention of fiber reduction. B. Prevention of heart disease.
C. Prevention of stroke. D. Prevention of cancer.
89. It can be inferred from the passage that a healthy diet .
A. needs enough proteins but no fat for us to maintain energy
B. is balanced between carbohydrates, and proteins and fats
C. is low in carbohydrates and high in proteins and fats
D. contains equal amounts of carbohydrates and proteins
90. The main purpose of the passage is to
A. promote more physical exercise
B. advocate a healthy diet
C. describe the variety of carbohydrates
D. explain how to live a healthy life
Passage Five
You never see him, but they're with you every time you fly. They record where you are going,how fast you're traveling and whether everything on your airplane is functioning normally. Their ability to withstand almost any disaster makes them seem like something out of a comic book.They're known as the black box.
When planes fall from the sky, as a Yemeni airliner did on its way to Comoros Islands in the India ocean June 30, 2009, the black box is the best bet for identifying what went wrong. So when a French submarine (潜水艇) detected the device's homing signal five days later, the discovery marked a huge step toward determining the cause of a tragedy in which 152 passengers were killed.
In 1958, Australian scientist David Warren developed a flight-memory recorder that would track basic information like altitude and direction. That was the first mode for a black box, which became a requirement on all U.S. commercial flights by 1960. Early models often failed to withstand crashes, however, so in 1965 the device was completely redesigned and moved to the rear of the plane – the area least subject to impact – from its original position in the landing wells (起落架舱). The same year, the Federal Aviation Authority required that the boxes, which were never actually black, be painted orange or yellow to aid visibility.
Modern airplanes have two black boxes: a voice recorder, which tracks pilots' conversations,and a flight-data recorder, which monitors fuel levels, engine noises and other operating functions that help investigators reconstruct the aircraft's final moments. Placed in an insulated (隔绝的) case and surrounded by a quarter-inch-thick panels of stainless steel, the boxes can withstand massive force and temperatures up to 2,000℉. When submerged, they're also able to emit signals from depths of 20,000 ft. Experts believe the boxes from Air France Flight 447, which crashed near Brazil on June 1,2009, are in water nearly that deep, but statistics say they're still likely to turn up. In the approximately 20 deep-sea crashes over the past 30 years, only one plane's black boxes were never recovered.