A、To transport water to higher elevation. B、To provide air-conditioning. C、To bring nutrients to the soil. D、To adjust the soil

Do you know that vegetables can be tricked into growing in climates they are not accustomed to? Cool climates vegetables like asparagus are now able to be grown in places as hot as Hawaii. In Hawaii, marine engineers have been able to actually convince such vegetables that they are living in cooler climates. That way they grow faster and taste better. What these engineers have been using is very simply cold seawater.
    How do they use it? They placed pipes in the soil and the cold water flowing through them cools the earth. This stimulates plant growth and enables gardeners in tropical climates to grow crops from cooler climates. Also, some of these pipes are exposed to the air and they condense moisture and thus irrigate the gardens. What is especially appealing about this process is that nothing damaging to the natural environment is being used.
    Another innovative use for cold ocean water is to cool buildings. Engineers believe that, for example, the entire west coast of the United States could be air-conditioned using seawater. We’ll be back to discuss that possibility after this commercial message.
Q. 23. What’s the report mainly about?
Q. 24.What does the new system enable the farmers to do?
Q. 25.How were the pipes used in Hawaii?
Q. 26.Why does the speaker mention air-conditioning?