题目
题型:不详难度:来源:
Lichens live on rocks, branches, houses, and even metal street signs. You can find these colorful organisms (微生物) almost everywhere — from deserts to rainforests, and from Antarctica to Africa. They’ve traveled in outer space, and some scientists think there might even be lichens on Mars.
What you probably don’t realize is that a lichen is more than a single thing. It includes two different types of living organisms: a fungus (菌类) and an alga (藻类). Neither of these organisms is a plant, so the lichen isn’t a plant either.
Through photosynthesis (光合作用), the alga gets the sun’s energy to make food for the fungus, which is the place for the alga to live in. However, the alga cannot leave the fungus.
Around the world, scientists have found tens of thousands of types of lichens. Many may not even have been discovered yet. As scientists continue to find new kinds of lichens, they are also working to understand how they are connected to one another. By putting together a lichen family tree, they hope to understand why so many different types of lichens have grown in so many places around the world.
Many researchers are trying to understand basic facts about the organisms and their connections. Researchers are also using lichens to examine the health of the environment.
小题1:What do we know about lichens according to the passage?
A.They will die if they leave Earth. |
B.There are more lichens than plants on Earth. |
C.They look similar to the environment around them. |
D.They are too small to be easily seen by people. |
A.The way lichens live. |
B.The natural environment of lichens. |
C.The way lichens work as organisms. |
D.The family tree of lichens. |
A.To understand basic facts about them. |
B.To creat a lichen family tree. |
C.To understand how lichens are related to each other. |
D.To understand why lichens can live in different places. |
A.lichens can be used to better understand the environment |
B.lichens don’t have any differences in colors or sizes |
C.lichens don’t use photosynthesis like a green plant |
D.scientists have discovered every kind of lichen |
答案
小题1:C
小题1:B
小题1:B
小题1:A
解析
核心考点
试题【Lichens (地衣) are difficult to see. They don’t move. They often mix into the livi】;主要考察你对题材分类等知识点的理解。[详细]
举一反三
When Peary returned to the United States, he went to a businessman to sell some furs. There he met Matthew Henson, an African American mechanic, builder and navigator. When Peary went to Nicaragua on a Navy mission(任务),Henson went with him. When that job was over, the two headed to the Arctic.
Henson and Peary set sail for Greenland. When they landed, Henson built a house for their base camp. Peary and his men set out to explore the land by dog sledge(雪橇). Henson was injured and had to stay at the base. While there, he made friends with the Inuit, the native people.
In 1895 Henson, Peary and Hugh Lee went out on another dog sledge journey. This time, they found Greenland’s northernmost point. They now knew that the North Pole lay under the frozen Arctic Ocean. Peary had hoped to cross the ice. but the group ran out of food and returned to base camp. In the years that followed, Peary and Henson tried several times to reach the North Pole, but each time they failed. On one trip, Peary’s feet froze, and he lost his toes(脚趾).
Peary and Henson planned last trip when Peary was 53 years old. They started across the sea ice from Ellesmere Island, which is located(位于) north of Canada. The temperature dropped as low as—51 degrees Celsius. The explores’ cheeks froze , and they suffered snow blindness from the sun’s glare. They experienced high winds and storms, and they also faced a hidden danger. Under the frozen ocean were powerful currents(潮流). The ice moved and broke apart leaving open water, called leads. Twice Peary fell into leads. But eventually he and Henson became the first persons to reach the North Pole.
小题1: What did Peary and Henson find in 1895?
A.Greenland is near the Artic Ocean. |
B.Ellesmere Island is located north of Canada. |
C.The North Pole is located in the Artic Ocean. |
D.Greenland’s northernmost point is the North Pole. |
A.Determined. | B.Modest. | C.Generous. | D.Honest. |
A.Snow blindness. | B.High winds. | C.Storms. | D.Leads. |
A.The mapping of the Arctic Ocean. |
B.Peary and Henson: Arctic explorers |
C.Early explorers’ trips to the South Pole |
D.Henson and Peary: discoverers of Greenland |
First-aid measures depend upon a victim’s needs and the provider’s level of knowledge and skill. Knowing what not to do in an emergency is as important as knowing what to do. Improperly moving a person with a neck injury, for example, can lead to permanent spinal(脊柱)injury and paralysis(瘫痪).
Despite the variety of injuries possible, several principles of first aid apply to all emergencies. The first step is to call for professional medical help. The victim, if conscious, should be reassured that medical aid has been requested, and asked for permission to provide any first aid. Next, assess the scene, asking other people or the injured person’s family or friends about details of the injury or illness, any care that may have already been given, and pre-existing conditions such as diabetes(糖尿病)or heart trouble. The victim should be checked for a medical card that describes special medical conditions. Unless the accident scene becomes unsafe or the victim may suffer further injury, do not move the victim.
First aid requires rapid assessment of victims to determine whether life-threatening conditions exist. One method for evaluating a victim’s condition is known by the acronym(首字母缩写词)ABC, which stands for:
A---Airway: is it open and clear?
B---Breathing: is the person breathing? Look, listen, and feel for breathing.
C---Circulation: is there a pulse? Is the person bleeding extremely? Check skin color and temperature for additional indications of circulation problems.
小题1: First aid may bring about all the following results EXCEPT____.
A.saving a victim’s life |
B.preventing a victim’s condition from getting worse. |
C.relieving a victim from pain |
D.helping a person avoid sudden illness or injury |
A.to make sure what to do and what not to do |
B.to refer to all kinds of handbooks on first aid |
C.to remove the ring or bracelet he/she may be wearing |
D.to take him/her to a hospital at once |
A.remove him from the accident scene | B.turn him over |
C.call for professional medical help | D.examine him carefully |
A.the importance of protecting the accident scene |
B.some basic facts about first aid |
C.what professional medical help is |
D.who can offer first aid |
Noah"s Ark is aimed at collecting eggs, embryos(胚胎),semen and DNA of endangered animals and storing them in liquid nitrogen(氮). If certain species should become extinct , Dr. Duane Kraemar, a professor in Texas A&M University Medicine, says there would be enough of the basic building blocks to reintroduce the species in the future.
It is estimated that as many as 2,000 species of mammals , birds reptiles will become extinct in over 100 years . The panda, native only to China , is in danger of becoming extinct in the next 25 years .
This week , Chinese scientists said they grew an embryo by introducing cells from a dead female panda into the egg cells of a Japanese white rabbit . They are now trying to implant the embryo into a host animal.
The entire procedure could take from three to five years to complete.
“The nuclear transfer(核子移植) of one species to another is not easy, and the lack of available(capable of being used) panda eggs could be a major problem,” Kraemer believes. “They will probably have to do several hundred transfers to result in one pregnancy(having a baby). It takes a long time and it’s difficult, but this could be groundbreaking science if it works. They are certainly not putting any live pandas at risk, so it is worth the effort, ”adds Kraemer, who is one of the leaders of the Project at Texas A & M, the first–ever attempt at cloning a dog.
“They are trying to do something that’s never been done, and this is very similar to our work in Noah’s Ark. We’re both trying to save animals that face extinction. I certainly appreciate their effort and there’s a lot we can learn from what they are attempting to do. It’s a research that is very much needed.”
小题1: The aim of “Noah’s Ark” project is to ________.
A.make efforts to clone the endangered pandas |
B.save endangered animals from dying out |
C.collect DNA of endangered animals to study |
D.transfer the nuclear of one animal to another |
A.available panda eggs | B.host animals |
C.qualified researchers | D.enough money |
A.China’s Success in Panda Cloning |
B.The First Cloned Panda in the World |
C.Exploring the Possibility to Clone Pandas |
D.China---the Native Place of Pandas Forever |
The bar-tailed godwit’s journey, from Alaska to New Zealand, covers over 6,835 miles. It completes this trip twice a year, in autumn going to New Zealand, and in spring back to Alaska. The tireless bird ends the trip without stopping once for food or rest. All other birds can only finish trips that are twice as short as what the bar-tailed godwit travels.
One reason for the bar-tailed godwit’s success is that it has made the best use of its fuel, which is only 0.41 percent of its body weight over each hour of any given long flight. Hedenstrom, a professor from Lund University, says, “This figure is extremely low compared with other birds.” The bird also has a special body shape that helps it fly easily. It stores body fat and protein to manage its trips. It also travels fast, compared to other birds and animals.
Many questions remain about this bird record holder that never gets lost in the air. Researchers wonder whether it has an inside compass (指南针) that helps it to know the direction. Please watch how beautiful bar-tailed godwits look as they come in for a landing, along with other birds.
小题1:For the flight from Alaska to New Zealand, the bar-tailed godwit__________
A.doesn’t need to stop to eat |
B.is afraid of hot weather |
C.seems very tired at last |
D.should fly less than 7,000 meters |
A.eats little food every hour |
B.has a special body shape |
C.stores much water in its body |
D.has very light body weight |
A.researchers have understood the bird very well |
B.the bird has a very good sense of direction |
C.there are still many who doubt the bird’s ability |
D.the bird has an inner compass |
On the Internet, English is the major language. As a result, it is now more important than ever to be able to understand English when you serve the web. It is not always easy,though. The English can be difficult or have a lot of cultural information that you have never seen !
One site for students studying English and their teachers is Englishtown. At http://www. english- town. com, you will find a community ( group) of people interested in learning English. There are several buildings in the virtual (虚拟的)town where you can play games, chat with friends, ask and get answers about cultural questions, and find an international penfriend who shares your interests. There are extra resources to help you learn,such as multimedia CD - ROM and books for language learning and translation. You can also have daily and monthly English lessons delivered to your own e - mail address. There is even an on - line school where you can take English classes over Lhe Internet. Englishtown is the perfect place to prefect for a trip to England or the United States ! Would you like to become part of a virtual community(虚拟社区)of English sfH-aktrs : Surfing the web is not only funny but can also help improve your English ! Try out >ome of tlv, web sites listed below and see how students all over the world are learning English on line.
小题1:Cyber English probably means" ".
A.learning English on Internet |
B.teaching yourself English |
C.the history of English |
D.English broadcast on TV or over the radio |
A.only in this way one can learn the language well |
B.people don’ t have to pay |
C.the learners can have a face to face study of courses with the teachers |
D.it makes learning easier and more interesting |
A.English is the only useful language on the Internet. |
B.The Internet can provide people with the cultural information they need. |
C.At http://www. Englishtown. com, people can study and play. |
D.One can find a pen-friend on http://www.Englishtown. com. |
A.setting up | B.going over | C.researching | D.inventing |
A.show us some of the web sites on which sell books |
B.tell us how to use the Internet |
C.tell us where to get the CD - ROMS we need |
D.show us some of the web sites on which English is taught |
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