Read the article and select the best answer. Article: Scientists have claimed a milestone in the drive for new energy--development of the first practical artificial leaf, an advanced solar cell that imitates the process,called photosynthesis ,that green plants use to make sunlight and water into energy. "A practical artificial leaf has been a dream of scientists for decades,"said Daniel Nocera,who led the research team."We believe we have made it.The artificial leaf shows particular promise as an inexpensive source of electricity for homes of the poor in developing countries. One can imagine villages in India and Africa soon purchasing an affordable basic power system based on this technology." The leaf is like the shape of a poker card but thinner.Placed in water in a bright sunlight,it could produce enough electricity to supply a house in a developing country with electricity for a day by splitting water into hydrogen and oxygen, which are stored in a fuel cell to produce electricity. The"artificial leaf"is not a new concept.The first artificial leaf was developed more than a decade ago by John Ttlrner.However, it was impractical for wider use,as it was composed of rare,expensive metals and was highly unstable with a lifespan of barely one day. Nocera's new leaf overcomes these problems.It is made of inexpensive materials that are widely available,works under simple conditions and is highly stable.Laboratory studies showed that it could operate continuously for at least 45 hours without a drop in activity. The key to this breakthrough is Nocera's recent discovery of several new powerful, inexpensive catalysts,which are able to accelerate the chemical reaction under simple conditions.Right now, Nocera's leaf is about 10 times more efficient at carrying out photosynthesis than a natural leaf.Yet he is optimistic that he can boost the efficiency of the device much higher in the future. Question: Daniel Nocera describes his artificial leaf as promising in _ . Options: A: making an artificial plant that can feed itself. B: finding a new kind of catalyst to produce electricity. C: changing the sunlight and water into electricity directly D: providing electricity for the poor family at a low cost
D

Read the article and select the best answer. Article: Seventeenth-century houses in colonial North American were simple structures that were primarily functional, carrying over traditional designs that went back to the Middle Ages. During the first half of the eighteen century, however, houses began to show a new elegance. As wealth increased, more and more colonist built fine houses. Since architecture was not yet a specialized profession in the colonies, the design of buildings was left either to amateur designers or to carpenters who were engaged in translating architectural handbooks imported from England. Inventories of libraries shows an astonishing number of these handbooks for builders, and the houses built during the eighteenth century show their influence. Nevertheless, most household architecture of the first-quarters of the eighteenth century displays a wide _ of taste and freedom of application of the rules laid down in these books. Increasing wealth and growing sophistication throughout the colonies resulted in houses of improved design, whether the material was wood, stone, or brick. New England still favored wood, though brick houses became common in Boston and other towns, where the danger of fire gave an impetus to the use of more durable material. A few houses in New England were built of stone, but only in Pennsylvania and areas nearby was stone widely used in buildings. An increased use of brick in houses and outbuildings is noticeable in Virginia and Maryland, but wood remained the most popular material even in houses built by wealthy landowners. In the Carolinas, even in closely packed Charleston, wooden houses were much common than brick houses. Eighteenth-century houses showed great interior improvements over the former ones. Windows were made larger and shutters removed. Large, clear panes replaced the small leaded glass of the seventeenth century. Doorways were larger and more decorative. Fireplaces became decorative features of rooms. Walls were made of plaster or wood. White paint began to take the... Question: The passage implies that the rules described in architectural handbooks were _ . Options: A: generally ignored B: broken by professional architects C: not strictly stuck to D: only followed by older builders
C

Q: Read the article and select the best answer. Article: Ruben lived in a small village. There was no school there and he had to study in a school in the town. It was nearly five kilometres away from his village. His father couldn't buy a bike for him and he had to go to school on foot. He got up early in the morning. Usually he had to run there in order not to miss the first class. He kept running every day and it was helpful to him. He's strong and tall now and he ran faster than any other man in his village. He took part in several sports meetings and won some medals. The young man is proud of(......)it and always wants to have a race with others. One day his mother was ill and his father told him to buy some medicine for headache in the town. The young man got there soon. There were many people in the chemist's shop while he was waiting there. And when his turn came, he could't find his money. An old woman hinted a young man had stolen it. He saw the thief had already left the shop. He ran towards him quickly. The thief found it and began to run. He was happy and tried to catch up with him. "Let's have a race and see who will run faster, "Ruben called out behind. Soon after that he caught up with the thief. But he didn't stop and went on running. At a crossing one of his friends asked, "What are you running for, Ruben? " "I'm running after a thief. " "Where's the thief, then? " "He wants to show that he'll run faster than me, but he's fallen behind!" Question: _ , so he won some medals. [ ] Options: A: Ruben is good at running B: Ruben went to school on time C: Ruben often took part in the sports meetings. D: Ruben likes to have a race with others
A: A

(Question)
Read the article and select the best answer. Article: On my first day in America, I was excited, but nervous as well. It was my dear neighbor Susan who helped me get used to my new life far away from home. There was a knock at the door. When I opened it, Susan came in with a home-made apple pie. She hugged me and said:"You must be the precious Chinese doll!" With a big smile, she went on:"Alice, I am sure you have never, ever tried a home-made apple pie before! You are going to love it so much!" To be honest, I was greatly surprised by this welcome from a stranger. And the apple pie made me feel at home. Susan was very helpful to me. When I was thinking about a costume to wear on Halloween, she suggested I dress up like a traditional Chinese girl. "I happen to have a traditional Chinese dress and guess what, I am a great make-up artist!" she said. Susan didn't hide her excitement, when, after an hour of hard work, she pushed me to the mirror to examine our work. The clothes fit me perfectly! I am sure that I _ from the crowd that Halloween, and I am very grateful to Susan for her help. My first Thanksgiving was another highlight. On the festival morning, I was surprised to find a gift box in my front yard. There was a note on it:"Hello Alice, I am the Thanksgiving bunny! Enjoy your gift!" I looked around and caught Susan looking at me from the porch. Seeing that she had been caught, she awkwardly picked up a newspaper and pretended to read it. I couldn't help laughing. When I walked up to her, she said:"It was not me. It was the Thanksgiving bunny!" Susan is such a lovely person; she is the American above all others I need to thank. I saw that the spirit of the Chinese saying, that "Neighbors carry more weight than distant relatives," is alive and well in America. Susan filled my heart with warmth and joy, just as angels do. Question: This passage is most probably taken from _ . Options: A: a newspaper B: a travel guide C: an advertisement D: a science magazine.
(Answer)
A