For many years scientists have said that the earth is getting warmer. Now they have found something new-hot cities! In the southern US, they have found that cities become very hot in summer. For example, the city of Atlanta in Georgia has roof(屋顶) temperature of up to 50^oC while it is 27℃ in the streets! At night, the outside of buildings stays so hot that the heat of the city causes storms over the city!
China also has the same kind of problems. Every year more farmland is used for factories or offices. More housing is needed, too. As people become richer, they buy more cars. New roads are needed and new car parks are built in the city centers. This all makes cities hotter.
It isn’t easy to change the situation. City planners say that we should plant more trees in the middle of cities. Every new street should have trees on both sides, they say. Trees make the temperature lower, so we should have more trees in our parks and squares. We should also paint our roofs white. If we do this, they do not become so hot. Every roof in a hot and sunny country should have solar(太阳的) roof panels. The electricity from these can be used to run the air conditioners (空调)in the buildings.
People continue to cut down forests around the cities. This makes the problem worse. Cities are growing faster and faster. By the year 2025, four fifths(五分之四) of the population will be living in cities. If we go on like this, there will not be enough farmland to feed everyone in the world
【小题1】The scientists have found       .

German scientists say that eating a little chocolate every day may keep you away from cardiovascular(心血管的) disease. The scientists have found that chocolate, especially dark chocolate , can help you cut down 39 percent of heart disease, including taking a very small amount . However, the study advises people not to eat too much chocolate, because too much chocolate is bad for our bodies. So the scientists advise people to eat small amount of chocolate instead of sugar or high-fat snacks.
Scientists said, “Dark chocolate shows the greatest effects, milk chocolate fewer , and white chocolate no effects.” The results showed chocolate may cut down blood pressure, but they also say that further study is needed.
In the eight-year study, people’s daily diet, exercise habits, and blood pressure were studied in 19,357 persons aged 35 to 65. They found that people who are an average of 7.5 grams of chocolate a day had a very lower chance of heart disease than those who ate much less chocolate , and average of 1.7 grams a day.
【小题1】It took the scientists __________ years to prove that small amount of chocolate is good for people.

根据句意和汉语提示写出单词，完成句子。
【小题1】Sally gets a lot of                (礼物) for her birthday.
【小题2】The scientists have designed many             （实验）to test the ability of dogs to see colour
【小题3】It’s said that the young man went abroad for further education alone in his             . (四十)
【小题4】           (八月)is the hottest month of a year.
【小题5】Please knock at the door before ___________ (进入) the room.