共用题干 Sharks Perform a Service for Earth's Waters It is hard to get people to think of sharks as anything but a deadly enemy. They are thought to1people frequently. But these fish perform a2service for earth's waters and for human beings. Yet business and sport fishing are threatening their3.Some sharks are at risk of disappearing from4. Warm weather may influence both fish and shark activity. Many fish swim near coastal areas5their warm waters. Experts say sharks may follow the fish into the same areas,6people also swim. In fact,most sharks do not purposely charge at or bite humans. They are thought to mistake a person7a sea animal,such as a seal or sea lion. That is why people should not swim in the ocean when the sun goes down or comes up.Those are the8 when sharks are looking for food. Experts also say that bright colors and shiny jewelry may cause sharks to attack. A shark has an extremely good sense of smell. It can find small amounts of substances in wa-ter,such as blood,body liquids and9 produced by animals. These powerful10help sharks find their food. Sharks eat fish,any11sharks,and plants that live in the ocean. Medical researchers want to learn more about the shark's body defense,and immune 12against disease. Researchers know that sharks13quickly from injuries. They study the shark in hopes of finding a way to fight human disease. Sharks are important for the world's14.They eat injured and diseased fish. Their hunting activities mean that the numbers of other fish in ocean waters do not become too15．This protects the plants and other forms of life that exist in the oceans. 8._________ A: times B: places C: seas D: oceans
共用题干 Paper or plastic? Take a walk along the Chesapeake Bay,and you are likely to see plastic bags floating in the water. Ever since these now ubiquitous symbols of American super-consumption showed up in the supermarkets,plastic shopping bags have made their______(51)into local waterways,and from there,into the bay,where they can______（52)wildlife. Piles of them一the______（53)takes centuries to decompose一show up in landfills and on city streets.Plastic bags also take an environmental toll in the form of millions of barrels of oil expended every year to produce them. Enter Annapolis______(54)you will see plastic bags distributed free in department stores and supermarkets.Alderman Sam Shropshire has introduced a well-meaning proposal to ban retailers ______(55) distributing plastic shopping bags in Maryland's capital. Instead,retailers would be required to offer bags______(56)recycled paper and to sell reusable bags.The city of Baltimore is considering a similar measure.Opponents of the idea,however,argue that______(57)bags are harmful,too:they cost more to make,they consume more______(58)to transport,and recycling them causes more pollution than recycling plastic.The argument for depriving Annapolis residents of their plastic bags is．______（59)accepted.Everyone in this______(60)is right about one thing:disposable shopping bags of any type are______(61),and the best outcome would be for customers to reuse bags instead.Annapolis's mayor is investigating how to hand out free,reusable shopping bags to city residents,a proposal that can proceed regardless of whether other bags are banned.A less-expensive______(62)would be to encourage retailers to give discounts to customers______(63)bring their own,reusable bags,a policy that a spokesman for the supermarket Giant Food says its chain already has in place.And this policy would be more______(64)if stores imitated furniture mega-retailer Ikea and charged for disposable bags at the checkout counter. A broad ban on the use of plastic shopping bags,which would merely replace some forms of pollution with others,is not the______(65). _________(60) A:competition B:fight C:quarrel D:debate
共用题干 Squishy Cellphones Add a Buzz to Calls Vibrating rubber could be the next big thing in mobile communications.They allow people to communicate by squishing the phone to transmit_______(51)along with their spoken words. According to a research team at the MIT Medical Lab in Cambridge,Massachusetts,the idea will make_______(52)more fun. Many mobile phones can already be made to vibrate（振动）_______(53 ) ring when you do not want people to know you are getting a call. But these vibrations,_______(54)by a motor spinning an eccentric（离心的、偏离的）weight inside the device, are too crude for subtle com-munication,says Angela Chang of the lab's Tangible Media Group.“They're_______(55)on or off,”she says. But when you grip Chang's prototype（样机）latex（橡胶）celiphone,your fingers and thumb wrap around five_______(56)speakers. They vibrate_______(57)your skin around 250 times per second.Beneath these speakers sit pressure sensors,so you can transmit vibration as well as_______(58)it. When you squeeze with a finger,a vibration signal is transmitted _______(59)your caller's corresponding finger. Its_______(60)depends on how hard you squeeze. She says that within a few minutes of being given_______(61)the phones,students were using the vibration feature to add emphasis to what they were saying or to interrupt the other speaker. Over time, people even began to transmit their_______ (62) kind of ad hoc（特别的）“Morse code”,which they would repeat back to show they were following what the other person was saying.“It was pretty easy to communicate,though we didn't specifically pre-arrange _______(63),”says David Milovich,one of the students who tried out the device. Chang thinks“vibralanguages”could_______(64)for the same reason as texting:some-times people want to communicate something_______(65)everyone nearby knowing what they are saying.“And imagine actually being able to shake someone's hand when you close a business seal,”she says. 62._________ A: .own B: unique C:.other D: different
