高考英语阅读冲刺：阅读理解12_高考复习指南

高考英语阅读冲刺：阅读理解12

　　Athey are not able to go to school

　　Bthey have to spend the whole day without a drink

　　Cthey have difficulty learning

　　Dthey must help their parents with housework

　　(D)

　　Why does cream go bad faster than butter? Some researchers think they have the answer, and it comes down to the structure(结构) of the food, not its chemical composition (成份)—a finding that could help break away from some chemicals. Cream and butter contain pretty much the same things, so why cream should go bad much faster has been a problem. Both are small globules(小球) of one liquid spread throughout another. The difference lies in what's in the globules and what's in the surrounding liquid, says Brocklehurst, who led the research. In careen, fatty globules drift about in a sea of water. In butter, globules of a watery road are locked away in a sea of fat. The bacteria(细菌) which make the food go bad prefer to live in the watery areas of the mixture. “This means that in cream, the

　　bacteria are free to grow throughout the mixture,” he says. When in butter, the bacteria are locked away in locked places buried deep in the sea of fat. Trapped in this way, those colonies cannot spread and rapidly run out. They also slowly poison themselves with their waste products.” In butter, you get a self-limiting system which stops the bacteria growing,” says Brocklehurst. The researchers are already working with food companies eager to see if their products can be made to stand bacterial attack through changes of the food's structure.