|
come into being; die out; according to; so that |
Many animals have disappeared during the history of the earth. The (famous) of these animals are dinosaurs. They lived on the earth (ten) of millions of years ago, long before humans came into (be). There were many different kinds of dinosaur and a number of them have been found in China. When inspecting (they) bones of a rare new species discovered in Chaoyang County, the scientists were surprised (find) they could not only run like other dinosaurs, but also climb trees. They could tell this from the way the bones (join) together.
Dinosaurs died quickly about 65 million years ago. Some scientists think it came after a large rock hit the earth. Others think the earth got hot for the dinosaurs to live on any more. Nobody knows for sure why and how dinosaurs disappeared from the earth in such short time. We know many other wild plants, animals, insects and birds (die) out more recently.
Climate change, not human hunting, may have destroyed the thylacine (袋狼), according to a new study based on DNA from thylacine bones.
The meat-eating marsupials (有袋动物)died out in mainland Australia a few thousand years ago, but survived in Tasmania, an island of southeast Australia separated from the mainland, until the 1930s. Until now, scientists have believed the cause of this mainland extinction was increased activity from native Australians and dingoes (Australian wild dogs).
Scientists behind the study of the University of Adelaide, which was published in the Journal of Biogeography on Thursday, collected 51 new thylacine DNA samples from fossil (化石)bones and museum skins. The paper concluded that climate change starting about 4, 000 years ago was likely the main cause of the mainland extinction.
The ancient DNA showed that the mainland extinction of thylacines was rapid, and not the result of loss of genetic diversity (基因多样性). There was also evidence of a population crash (大跌)in thylacines in Tasmania at the same period of time, reducing their numbers and genetic diversity.
Professor Jeremy Austin said Tasmania would have been protected from mainland Australia's warmer, drier climate due to its higher rainfall. He argued that climate change was "the only thing that could have caused, or at least started the extinction on the mainland and caused a population crash in Tasmania".
"They both occurred at about the same time, and the other two things that have been talked about in the past and that may have driven thylacines to extinction on the mainland were dingoes and humans. So the only explanation that's left is climate change. And because that population crash happened when the species went extinct on the mainland, our argument is that there's a common theme there and the only common theme is that there is this change in climate."
The monarch's journey
This annual movement is called migration. They migrate to find food, seek a partner, or in search of warmer weather. One of the most wonderful migrations in nature is that of North American monarch butterfly.
Every autumn, millions of these beautiful insects with fine black and orange wings begin a long and difficult journey. Somehow they manage to travel around 4, 000 kilometres south and find their way to California or Mexico.
A team of scientists led by Professor Eli Shlizerman at the University of Washington has now found the answer. It uses its eyes to measure the position of the sun. These two pieces of information—the time of the day and the position of the sun—allow the butterfly to determine the way to go. Eventually it manages to reach the places where it will spend the winter.
The solution to the mystery of the monarch's amazing ability comes at a time when it is in serious trouble. Its population has crashed by as much as 90% in the last few years. The research on the monarch's behaviour has however led to a greater awareness of this creature. People have been working together to record its migration and make sure that there are enough plants for it to feed on. The more we know about this lovely creature, the more probably it will survive and keep its place in the natural world for a long time to come.
A. Animals migrate for different reasons.
B. However, no one knew how they did this.
C. They've found out that the monarch is able to tell the time of the day.
D. Many animals move from one place to another at certain times of the year.
E. If this works, the number of monarch butterflies might increase once again.
F. They examined monarch butterflies closely and have got first-hand information.
G. Sadly, human activity is the main reason why the number of monarch butterflies is falling.
Chito Shedden was a simple fisherman and tour guide from Siquirres, Limon Province, Costa Rica. He had a broad range of interesting facts about nature, which helped his business quite a bit.
The year was 1989 and Chito was walking along the banks of the Reventazón River when he happened upon something very strange. There was a dying male crocodile(鳄鱼). When he stepped up to carefully examine the skinny reptile, he realized it had been shot through the head and then the left eye.
He knew, dangerous as it was, he couldn't leave the poor animal there, alone and helpless. Chito acted quickly, asking several brave friends to load the heavy reptile into his boat. He knew if he could heal it, he would then send it back into the wild. He named the huge reptile "Pocho", which means strength, and began to care for him in his own backyard.
The kind and helpful fisherman started to heal Pocho with medicine, food, and more importantly, lots of care and attention. Chito fed the crocodile a steady diet of chicken and fish. He bought medicine to prevent infection(感染) and even slept by his side at night.
Affection was one of the most important factors. Chito gave him kisses and hugs. He talked to him and petted him. "The crocodile needs my love to regain the will to live, " he said. In time, Pocho improved enough and returned to normal health. It was time for him to return to his own river in the wild. Chito and his friends loaded the crocodile back into his boat and set him free in a nearby river. The two parted ways and Chito returned home alone.
注意：续写词数应为150左右。
Paragraph 1:
Chito awoke the next morning, and walked outside.
Paragraph 2:
A closer relationship was formed between Pocho and Chito.
