Climate change has caused a rise in sea levels. This has increased the amount of salt in fresh water ____(use) on coastal farms. As a result, farmers are ____(gradual) unable to use fields close to the sea. However, Marc Van Rijsselberg, a farmer in the Netherlands is now using a ____(mix) of sea and fresh water ____(grow) healthy and tasty vegetables.

    He teamed up with scientists from the Free University and divided a farm ____eight negated areas. Separate pipes pumped fresh and sea water, and a computer program created water with eight levels of salinity (含盐度).

    The water levels and the levels of salinity was ____(control) by computerized measuring devices called “sensors”. Mr. Van Rijsselberg said he was able to harvest vegetables from most of the eight testing areas. He said the vegetables were smaller than ____ grown in fresh water. But he said they also had more sugar and salt, so they tasted much ____(good).

    He found that potatoes grew better than the other vegetables in the combination of sea and fresh water. Mr.Van Rijsselberg said four kinds of these potatoes would be sent to Pakistan ____thousands of hectares of land ____(damage) by salinization last year.

太阳活动强弱最主要的标志是____，大气中的臭氧层位于____层。