75．It can be inferred from the passage that ________.

　 　　 A．sea water can act as an air-conditioner

　　　 B．asparagus are only grown in hot places

　　　 C．the writer wants to tell us something about scientific advance

　　　 D．sea water has many advantages

74．What is the report mainly about?

　　　 A．How to grow vegetables in hot areas. 　

　　　 B．How to grow crops in tropical climates.

　　　 C．How to cool the soil.　　　　　　 　　

　　　 D．How to use sea water.

73．Sea water mentioned in the passage is mainly used to________.

　 　 A．water the farms　　 　　　　　　　　　　　　　 B．water the gardens　　

C．cool the air　　　 　　　　　　　　　　　　　　　 D．make the earth cool

72．What does the new system enable the gardeners to do?

　 　 A．Water the field with seawater.　　　　　　　

　　　 B．Grow asparagus in hot places.

　 　 C．Grow cool climate vegetables in hot areas.　　　　　　　　　　　　　　　　　　　　　　　　　　

　　　 D．Cool the soil.

71．In larger cities, the fumes from coal and oil may contribute to ___________.

A．heart disease　 　 　　　　　　　　　　　　　　　 B．lung diseases　 　　 　

C．loss of clear vision　　 　　　　　　　　　　　　 D．serious headache

　　　　　　　　　　　　　　　　　 E

Did you know that vegetables can grow in the climates they are not used to? Cool climate vegetables like asparagus (芦笋) are now able to be grown in places as hot as Hawaii. In Hawaii, marine (海的)engineers have been able to actually let you believe such vegetables that they are living in cooler climates. In that way they grow faster and taste better. What these engineers have been using is very simply cold sea water. How did they use it? They place pipes in the soil and cold water flowing through them cools the earth. This causes plant growth and enables gardeners in tropical climates (热带气候) to grow crops from cooler climates. Also some of these pipes are exposed to the air and they make the air “wet” and thus water the gardens. What especially makes people happy about this process (过程) is that nothing to the natural conditions is being used. Another new 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.

70．The fumes from coal and oil may cause metal ______.

A．to turn black　 　　　　　　　　　　　　　　　　　 B．to become rusty　 　　　　　　　　　　　　　　　

C．to corrode　 　　　　　　　　　　　　　　　　　　　 D．to twist