Directions: In this section, there are four passages followed by questions or unfinished statements, each with four suggested answers A,B.C andD.Choose the best answer and mark your answer on the ANSWER SHEET.

Passage Three

　　Many large businesses in developing countries have high energy costs.They spend money for air-conditioning systems to keep people cool and they spend money for heating systems to produce hot water.A company in the Philippines sells a system that saves energy costs by doing both jobs at once.The system uses the waste heat from air-conditioners to heat the water supply.The publication Energy Alternatives has described this system.The publication reports on efforts to save energy in the Philippines.

　　An air-conditioner produces cool air.It works by pulling in the air from a warm room.It forces the air through a long, cold tube.The tube cools the air flowing inside.Then the air-conditioner blows this cool air back into the room.The waste heat is blown to the opposite direct out of the window.A technology called heat recovery catches this waste heat and uses it to create hot water.An American company in the state of Florida makes heat recovery systems.A company in the Philippines, Electro-system Industries, sells them locally.The company first put heat recovery systems in housing project for American soldiers in the Philippines.The housing project has several larger air-conditioners.The heat recovery systems capture waste heat from these air-conditioners and use it to produce hot water.This has reduced the need to produce hot water in some other way.As a result, fuel costs have dropped.Next, the company put a heat system in a McDonald’s restaurant.The restaurant needed a lot of air-conditioning and hot water at the same time.The new system helped it re- duce energy costs while getting more hot water.The McDonald Company now plans to use such systems in all its restaurants in the Philippines.

　　Heat recovery systems like these are too big and costly for private homes, but they can work well for businesses that need air-conditioning and hot water in large amounts at the same time.Goods stores, hotels, hospitals and factories in warm countries all may find them a good way to cut energy costs.The American supplier says energy saving can pay for the system within six months to two years.The amount of time depends on how this system is used.
An ordinary air-conditioner _____.

A.virtually

B.remarkably

C.ideally

D.preferably