Despite increased airport security since September 11th, 2001, the technology to scan both passengers and baggage for weapons and bombs remains largely unchanged. Travellers walk through metal detectors and carry-on bags pass through x-ray machines that superimpose colour-coded highlights, but do little else. Checked-in luggage is screened by "computed tomography", which peers inside a suitcase rather like a CAT scan of a brain. These systems can alert an operator to something suspicious, but they cannot tell what it is.
More sophisticated screening technologies are emerging, albeit slowly. There are three main approaches: enhanced x-rays to spot hidden objects, sensor technology to sniff dangerous chemicals, and radio frequencies that can identify liquids and solids. A number of manufacturers are using "reflective" or "backscatter" x-rays that can be calibrated to see objects through clothing. They can spot things that a metal detector may n
A. A generalization is made in paragraph 2 and then elaborated in paragraph 3,4 and 5.
B. More sophisticated screening technologies are mentioned in paragraph 2 and 3 and then examples are provided in paragraph 4 and 5.
C. Specific evidence is provided in paragraph 1,2 and 3 and then a conclusion is drawn in paragraph 4.
D. Three main approaches are advanced in paragraph 2,3 and then their functions are detailed in paragraph 4 and 5.
| It’s navel gazing time again, that
stretch of the year when many of us turn our attention inward and think about
how we can improve the way we live our lives. But as we embark on this annual
ritual of introspection, we would do well to ask ourselves a simple question:
Does it really do any good The poet Theodore Roethke had some insight into the matter: "Self-contemplation is a curse that makes an old confusion worse." As a psychologist, I think Roethke had a point, one that’s supported by a growing body of controlled psychological studies. In a study I conducted with Dolores Kraft, a clinical psychologist, and Dana Dunn, a social psychologist, people in one group were asked to list the reasons their relationship with a romantic partner was going the way it was, and then rate how satisfied they were with the relationship. A. Leave them alone to adjust their emotions. B. Provide them with consultation about their jobs. C. Help them figure out what has happened. D. Discuss with them how to do it better next time. 我来回答: 提交
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