A、To transport water to high places. B、To provide air conditioning. C、To fertilize the soil. D、To adjust the soil temperature. D

Do you know that vegetables can be grown in climate they are not accustomed to? Cool climate vegetables are now able to be grown in places as hot as Hawaii.
    In Hawaii, engineers have been able to actually make those vegetables live in cooler climates. That way they grow faster and taste better. What these engineers have been using is cold seawater. The temperature of seawater is much lower than the air temperature.
    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 make the moisture form little water drops 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 coal buildings. Engineers believe that, for example, the entire west coast of the United States could be air-conditioned using seawater.
    We all know there are certain types of chemicals used in air conditioners, which not only pollute the air but also bring damage to the ozone. If we could cool the city by using seawater, the environment of the whole city will be improved and the ozone will be protected, which will be beneficial to ourselves in return.