A little old couple walked slowly into McDonald’s one cold winter evening. They were so old that they looked out of place amid the young families and young couples eating there that night.

　　Some of the customers looked admiringly at them. You could tell what the admirers were thinking. “Look, there is a couple who has been through a lot together, probably for 60 years or more!”

　　The little old man walked right up to the cash register, placed his order with no hesitation and then paid for their meal. The couple took a table near the back wall and started taking food off the tray. There was one hamburger, one order of French fries and one drink. The little old man unwrapped the plain hamburger and carefully cut it in half. He placed one half in front of his wife. Then he carefully counted out the French fries, divided them in two piles and neatly placed one pile in front of his wife. He took a sip of the drink, his wife took a sip and then set the cup down between them.

　　As the man began to eat his few bites of hamburger the crowd began to get restless. Again you could tell what they were thinking, “That poor old couple. All they can afford is one meal for the two of them.”

　　As the man began to eat his French fries one young man stood and came over to the old couple’s table. He politely offered to buy another meal for the old couple to eat. The old man replied that they were just fine. They were used to sharing everything.

　　Then the crowd noticed that the little old lady hadn’t eaten a bite. She just sat there watching her husband eat and occasionally taking turns sipping the drink.

　　Again the young man came over and begged them to let him buy them something to eat. This time the lady explained that, no, they were used to sharing everything together.

　　As the little old man finished eating and was wiping his face neatly with a napkin the young man could stand it no longer. Again he came over to their table and offered to buy some food.

　　After being politely refused again, he finally asked a question of the little old lady. “Ma’am, why aren’t you eating? You said that you share everything. What is it that you are waiting for?”

　　She answered, “ The teeth”.

46.The underlined phrase in the first paragraph most probably means ______________.

       A. looked helpless    B. looked romantic  

       C. looked unsuitable  D. looked cheerful

47.Why did some of the customers admire them?

A.Because they walked in hand in hand.

B.Because they come to McDonald’s together.

C.Because they have been together for many years

D.Because they come in such a cold winter evening

48.How much food did the man get?

A.One hamburger, one French fries and one cup of tea

B.One hamburger, two French fries and two cups of tea

C.One hamburger, one French fries and two cups of tea

D.One hamburger, two French fries and one cup of tea

49.How did the young man feel about what he saw in the old couple?

A. Admiring   B. Bad    C. Good    D. Guilty

50.Why didn’t the old lady eat her portion of meal?

A.Her artificial teeth didn’t fit her well.

B.She forgot to bring her teeth with her.

C.Her husband had not finished using the teeth.

D.She was waiting for someone to get her teeth for her.

　　For years scientists have been worried about the effects of air pollution on the earth’s natural conditions. Some believe the air inside many houses may be more dangerous than the air outside. It may be one hundred times worse.

　　Indoor air pollution can cause a person to feel tired, to suffer eye-pain, headache and other problems. Some pollutants（ 污染 物） can cause breathing disorders, diseases of blood and even cancer, Most scientists agree that every modern house has some kind of indoor pollution. People began to notice the problem in the early 1970s. It is that when builders began making houses and offices they did not waste energy. To do this they built buildings that limited the flow of air between inside and outside. They also began using manmade building materials. These materials are now known to let out harmful gases. As the problem became more serious, scientists began searching for a way to deal with it. They discovered a natural pollution control system for building— green plants. Scientists do not really know how plants control air pollution. They believe that a plant’s leaves absorb or take in the pollutants. In exchange the plant lets out oxygen through its leaves and through its tiny organizations on its roots. Scientists suggest that all buildings should have one large plant or several small plants inside for every nine square metres of space. Studies of different plants show that each absorbs different chemicals. So the most effective way to clean the air is to use different kinds of plants. Having green plants inside your house can make it a prettier and more healthy place.

　　Generally speaking, indoor air pollution may be more harmful than the air outside because ________.

　　A. the man - made building materials let out dangerous gases inside houses

　　B. there may be more harmful gases outside houses

　　C. the flow of air indoors is limited

　　D. indoor air pollution can make a person seriously ill

　　The most effective way to clean the air is to use different kinds of plants because________.

　　A. they may let out more oxygen which people need

　　B. they can absorb different kinds of the harmful indoor chemicals

　　C. they can take in all kinds of indoor pollutants

        D. they can make your house prettier and more healthy