Having farmed in Florida for the past 35 years, Ed Rawling is prepared for the frosts . When temperatures drop below freezing, Rawling tries to save his crop by watering his orange trees. The water freezes and forms a thin layer of ice on the trees. Strange as it may sound, this thin layer of ice actually keeps the fruit warm.

What happens is simple. When the trees are watered, the water loses heat and becomes ice. The warmth of the heat it loses is sucked in (吸收) by the fruit and keeps its temperature at a safe level. But Ed still faces some difficulties. The trees should be watered at the exact moment the temperature drops to the freezing point. Also, just the right quantity of water must be used. Too much water can form a thick layer of ice that will break the tree’s branches . Another difficulty is that wind blows away the heat. So Ed has to worry about not only when but also how often his trees should be watered , and how much water should be used .

Computer technology may help Ed Rawling with some of these worries. With equipment , air and soil temperatures and wind speed can be measured. The information is fed into a computer which can tell when temperatures drop to freezing. The computer can correctly decide the quantity of water to be used and how frequently the trees should be watered. Ed Rowling will find looking after his orange trees a lot easier with the help of a computer.

1. The text is mainly about ___________ .

A. a farmer’s professional care for his orange trees

B. the different uses of computers

C.growing oranges in Florida’s changeable weather

D. different ways of forest prevention

2. How did Ed try to protect his orange trees?

A. He used a wind machine to drive away the cold air.

B. He equipped his orange trees with a computer.

C. He watered them with proper quantity of water at proper time.

D. He picked the fruit at the first sign of frost .

3. Which of the following is NOT the difficulty that Ed Rawling has to face?

A. The trees should be watered when the temperature drops to the freezing

point.

B. The trees should be watered with the right quantity of water.

C. The trees should be watered with a proper frequency.

D. He doesn’t know how to use the computer to control all this work.

4. In the writer’s opinion, computers __________.

A. are too expensive for small farms

B. can be valuable tools for the farmers

C. can be used to help orange grow bigger

D. can’t replace farmers’ experience

5. Which of the following statements is NOT necessary for Ed Rawling to do?

A. He has to water the orange trees when temperature drops to freezing point.

B. He has to decide the quantity of water used for the orange trees.

C. He has to judge how often he has to water his orange trees.

D. He has to water more water to the orange trees when temperature drops to freezing point.

ACDBD