When building houses, people used to think about not only the climate of the areas but also the building materials and the fashions for their houses. However, since electricity became more and more expensive, people began to pay much more attention to the energy they could get for their houses and the new ways they could find to protect their houses from both cold and heat.

     Now, houses of an old yet new type have been widely built. In some parts of the world, people share their houses with their livestock（家畜）.During cold weather, they gather their cows, goats, or other animals and keep them on the first floor of their houses. The reasons are that the animals can be protected from the cold and that they can help to heat the houses as well. The body heat given off by the animals rises to the second floor of the houses, where people live. By sharing their houses with their livestock, people gain a source of heat.

     People who live in or near cities do not usually keep livestock. However, home builders use the fact that heat rises. This natural law can be used in building houses in these areas. Instead of keeping livestock on the first floor, builders fill it with large rocks. As they are open to the sun’s rays during cold weather, these rocks take in heat. They also give off the heat, and, of course, the warm air rises into the living areas of the houses. So these houses are energy-saving.

     House-building becomes a great challenge（挑战）to building designers and energy engineers. They try to meet this challenge by learning from old traditions and by using modern technology. And someday in the future, people will be able to live in more energy-saving houses.

56．What did people begin to consider as electricity was no longer cheap?

      A．The climate of their areas.                    B．The energy for their houses.

      C．The fashions for their houses.               D．The building materials for their houses.

57．People in some areas gain a source of heat by _________.

       A．keeping their livestock downstairs        

    B．protecting their livestock from the cold

       C．sharing their houses only with their cows                             

       D．living on the second floor with their livestock

58．The underlined words “natural law” in the third paragraph refer to the fact that ________.

       A．heat raises the temperature in the houses

       B．heat goes in the upward direction

       C．heat goes up if temperature is raised

       D．heat increases the temperature of rocks

59．From the passage, we can conclude that __________.

       A．people will no longer consider building materials in the future

       B．energy-saving buildings will become more popular in the future

       C．almost all people will move into the houses heated by large rocks

       D．energy engineers will devote themselves only to modern technology

Dinosaurs now are far away from us. Dinosaurs were real animals that once lived on the earth, but they _1_ (die) out about 65 million years ago. The _2_(disappear) of the dinosaurs is _3_ some way a great mystery. Some scientists think that the climate changed suddenly. Fossils of trees tell us that the temperature dropped a lot and that the level of the sea dropped as well. This means that it got suddenly much _4_ (cold). Perhaps the dinosaurs were too slow __5__(change) with the climate. A new idea is _6_ a meteor(流星) crashed into the earth. Scientists discovered a place in Mexico _7_ they think the meteor crashed. They think that there was a lot of dust from the meteor. The dust landed on the plants. Also the dust blocked(阻挡)the sun’s light for as long as five years. Many animals, _8_ (include) dinosaurs, were plant eaters, and perhaps the dust killed __9___. This means there was nothing left for meat eating dinosaurs to eat, and so they died out. But, as many animals from that time did not die, we are not 100% sure what ___10__ (real) happened.

Vitamin D helps bones and muscles grow strong and healthy. Low levels of vitamin D can lead to diseases such as rickets (佝偻病), mainly found in children. The thinning of bone is a common problem as people, especially women, get older.
But more and more research is suggesting that vitamin D might also help prevent many diseases. The easiest way to get vitamin D is from sunlight. The sun’s ultraviolet (紫外线的) rays react with skin cells to produce vitamin D. But many people worry about getting skin cancer and skin damage from the sun. As a result they stay out of the sun. Also, darker-skinned people produce less vitamin D than lighter-skinned people. The amount also decreases in older people and those living in northern areas that get less sunlight.
Not many foods naturally contain vitamin D. Foods high in this vitamin include oily fish and fish liveroils (鱼肝油). Farmed fish have only about one-fourth as much vitamin D as wild fish. Small amounts of vitamin D are found in beef liver, cheese and egg yolks. But most of the vitamin D in the American diet comes from foods such as milk.
Research in the last several years has shown that low levels of vitamin D may increase the risk of heart attacks in men and deaths from some cancers. More doctors are now having their patients tested for their vitamin D levels. But as research continues, some experts worry that if people take too much vitamin D, it might act as a poison. Also, skin doctors warn people to be careful with sun exposure because of the risk of skin cancer.
【小题1】The first paragraph is mainly about 　　　　.

Travelling around the world with children is difficult enough, but attempting it without using motorized transport is even more of challenge. But Dario Schworer, a 42-year-old climatologist and mountain guide, and his 33-year-old wife Sabine are on a journey to do just that.
The Swiss couple want to travel across the world’s oceans and climb the highest mountain on every continent to promote Earth-friendly ways of life.
“We are collecting good examples of dealing with climate change and living in harmony with nature and we want to spread such ideas,” Schworer said. “We want to help people affected by global warming and to inspire children for the future.”
Recently after having spent three months teaching children in the Everest region, the couple want to show it is possible to travel through as the world’s climate zones using just human-power and forces of nature.
In the 47 countries they have visited so far they have collected 22 tons of trash, taught people in Ecuador how the sun’s rays can be used to clean water and inspired a person in Chile to build a house on water with recycled plastic bottles as a foundation. They have also collected trash in the mountains of Nepal with school children.
So far they have communicated with 45,000 children from South America, Australia and Asia, giving presentations about the importance of recycling and using alternative energy like solar and wind power.
“We need to motivate children,” said Sabine.
When they began their adventure in 2003 they had no children of their own. But since then two has become five: daughter Sabine is now five years old, Andri was born in Chile and baby Noe was born in Australia.
Initially the couple thought they would complete their travels in four years, but now, seven years later, they believe it could take seven more.
“Since our belief is the need to respect nature, we travel only when conditions are good,” Schworer said.
【小题1】Why do the Swiss couple travel around the world?