一份关于酸雨的报告总结道,“加拿大的大多数森林没有被酸雨损害。”这份报告的批评者坚持认为这一结论必须改变为,“加拿大的大多数森林没有显示出明显的被酸雨损害的症状,如不正常的落叶、生长速度的减慢或者更高的死亡率。” 下面哪个,如果正确,为批评者坚持要改变报告结论提供了逻辑上最强有力的正当理由?
A. 加拿大的一些森林正在被酸雨损害。
B. 酸雨可能正在造成症状尚未明显的损害。
C. 报告没有把酸雨对加拿大森林的损害与酸雨对其他国家森林的损害进行比较。
D. 过去的15年内,加拿大所有森林都下过酸雨。
E. 酸雨造成的损害程度在不同森林之间具有差异。
The average automatic teller machine (ATM) is not very smart. It will give money to anyone who has the right card and punches four or five keys in the right order. Some analysts estimate that as many as 30% of ATM transaction worldwide are cases of theft. To increase security at cash machines, some banks have tried to make their ATMs a little smarter. A small camera on the machine looks directly into the eye of every customer. It scans one iris and compares the tiny patterns of ridges, dots, and other features to a code in its computer. If there is a match, the ATM will start counting out cash. If not, a message is automatically sent to the nearest police station. Iris-scanning is one fast-growing form of biometric identification --- determining who someone is by examining features the body. One of the earliest biometric techniques was fingerprinting. The line on fingerprints are unique to each person, so not even identical twins have the same fingerprints. Fingerprinting has become famous as a way of finding out who committed a crime, but it very often fails. A careful criminal can swear gloves, avoid touching thing, or even alter his fingerprints by burning, cutting, or scraping them. In the search for a more reliable system, security experts have focused on the eye. Like a fingerprint, every iris is, for all practical purposes, unique. Each person’s right iris is even different from his or her left one. A low-cost digital camera, like the kind installed at ATM machines, can easily detect hundreds of different features in the iris. The chance of two irises having the same features is close to zero. Tests have shown that iris-scanners are very hard to fool. They can tell the difference between a real iris and a false one. They can see right through colored contact lenses, eyeglasses, and even mirrored sunglasses. Although many criminal are willing to burn or cut their fingers in pursuit of the perfect crime, few would be willing or able to alter their irises. To make iris-scanning work, a computerized database has to match certain iris features with certain people. This means that each ATM customer has to allow a bank to photograph his or her iris and keep that highly personal information in a computer. Some people have worried, however, that an increased use of iris-scanning will lead to a dangerous loss of privacy. By mounting iris-scan cameras in public places, governments could track a private citizen all day long without the person’s knowledge. This would be a great advantage to the police, but it could also give corrupt officials a new way to control their opponents. The military’s development of tiny robots suggests that government iris-scanners could even invade private homes! Questions 1-5 Complete the summary with words from the passage, changing the form where necessary, with only one word for each blank. ATM transactions are often cases of theft, where an unauthorized user takes (1) ___. To decrease insecurity, some banks have installed iris-scanning machines at ATMs. These small cameras scan the user’s iris, recording its features and (2) ____ them to a digital file. Every person has a (3) ____ iris, making iris identification highly reliable. Earlier efforts at biometric identification often relied on fingerprints. However, fingerprints can easily be (4) ____ through cutting, burning or scrapping. Iris scanners are so effective that they can even see through contact lenses and mirrored sunglasses. Use of iris scanners would provide great advantages to the police. However, others worry about a loss of (5) ____.