C．set up a house

　　　D．leave a certain amount of time

　　　 Vinegar makes salad，fries and dumplings taste better， and you can even use it to clean your windows． And now， according to scientists， it may even the planet's population survive climate change．

　　　Researchers from the RIKEN Center for Sustainable Resource Science （CSRS） in Japan found that growing plants in vinegar makes them more resistant to droughts． This could mean that in the future， worries about climate change affecting the world's supply of food will be much lower． The discovery was made after the researchers studied the Arabidopsis， a plant known for its ability to survive in dry weather． It was found that when the plant was placed in drought﹣like conditions， it produced a chemical called acetate（醋酸盐）﹣the main component of vinegar．

　　　After discovering this， the scientists experimented further by adding acetate to the soil of other plants， before they stopped giving them water completely． After leaving the plants for 14days， they found that the ones treated with acetate had survived， while the untreated plants had dried up and died．

　　　It's hoped that this simple method of survival could soon be used to help farmers in dry countries keep their crops alive． "In the experiment， we targeted the staple foods of the world﹣rice， wheat and maize﹣and the basic plant of breeding species， rapeseed（油菜籽），" Jong Myong Kim， co﹣author of the study， told Popular Science magazine．

　　　Kim also told the magazine he's already been in touch with people all over the world who are interested in trying this simple and cost﹣effective method out for themselves from flower growing companies to amateur gardeners． Although at this point keeping thirsty plants alive isn't as easy as just pouring vinegar over them， Kim said he and his team are working on making the process as simple as possible． "Now we are trying to cooperate with some farmers， and also some companies， to make a method to apply this system， "he said． And for those of us who always forget to ask our neighbors to water our plants when we goaway， hopefully this means the end of returning home from a trip to find our favorite flowers have died．

　　　12．What is the article mainly about？

　　　A．The world's food supply will be increased．

　　　B．Plants better survive droughts．

　　　C．The Arabidopsis is resistant to droughts．

　　　D．Vinegar could be used to fight droughts．

　　　13．It was discovered that acetate can　 　．

　　　A．be used by farmers to replace soil

　　　B．only be produced by the Arabidopsis

　　　C．help plants survive dry conditions

　　　D．be used to improve poor soil

　　　14．What are the target plants of the experiment？

　　　A．all breeding species．

　　　B．wheat and Arabidopisis．

　　　C．rice and maize．

　　　D．rapeseed and Arabidopisis．

　　　15．Jong Myong Kim's experiment of trying out the method　 　．

　　　A．can make people's trips pleasant

　　　B．turned out a worldwide success

　　　C．is as simple as pouring vinegar over the plants

　　　D．appeals to many flower growing companies

二、七选五

　　　Avoid Internet Addiction

　　　16． Many people suffer from addition to the Internet and have a hard time paying attention to the important things around them．How can we prevent ourselves from going online too much？

　　　Admit you have an addition．17． Realize more and more people in the world are becoming addicted．You are not the only one with ths problem．Do not be embarrassed； find others with the same problem and help each other beat it．

　　　Limit your computer time．Make sure not to turn it on too many times a week．Befoe using your computer，decide on a time limit such as 30 minutes．Set the clock and make sure that you get off he computer when the time is up．18．

　　　Try using the computer at the library．You won't be as attracted to look at certain websites and they do have a limit on how long you can stay online．19．．So you won't be as attracted to be on the Internet as at home．

　　　20． Go for a run with a friend or get exercise some other way．Keep up with the local events in your neighborhood．There may be talks，films，concerts and sports events etc．Find some，as long as it is not on the Internet，and get involved．

　　　A．You will be happier if you use the Internet less．

B．There is no use avoiding the truth．