题目
题型:不详难度:来源:
The trunk of redwood trees is very strong and usually forms a single straight column.It is covered with a soft bark.This bark can be pretty thick,well over two feet in the more mature trees.It gives the older trees a certain kind of protection from insects,but the main benefit is that it keeps the center of the tree harmless from moderate forest fires because of its thickness.This fire resistant quality explains why the giant redwood grows to live that long.While most other types of trees are destroyed by forest fires,the giant redwood actually prospers because of them.
Moderate fires will clear the ground of competing plant life,and the rising heat dries and opens the ripe fruit of the redwood,releasing many thousands of seeds onto the ground below.
New trees are often produced from shoots,little baby trees,which form at the base of the trunk.These shoots grow slowly,fed by the root system of the “mother’’ tree.When the main tree dies,the shoots are then free to grow as full trees,forming a “fairy ring” of trees around the original tree.These trees,in turn,may give rise to more shoots,and the cycle continues.
小题1:Why were redwood trees easier to find in the forests of North America millions of years ago?
A.The trees were taller and stronger. |
B.The soil was softer for seeds to develop. |
C.The climate there was warmer and wetter. |
D.The temperature was lower along the Pacific coast. |
A.It allows redwood trees to bear seeds. |
B.It prevents redwood trees from attack by insects. |
C.It helps redwood trees absorb water in the air. |
D.It makes redwood trees more beautiful and appealing. |
A.They have heavy and straight tree trunks. |
B.They are properly watered and catered to. |
C.They are more resistant to fire damage than other trees. |
D.They produce many young trees to maintain their life cycle. |
A.By killing an old tree. | B.By connecting root systems. |
C.By inserting holes into old trees. | D.By surrounding a mature tree. |
答案
小题1:C
小题2:B
小题3:C
小题4:D
解析
试题分析:文章介绍红杉的生长习性,它怎么抵御昆虫和森林大火的侵害,怎么能够存活的那么久。
小题1:细节题:从文章第一段的句子:A hundred million years ago,in the age of dinosaurs,redwoods were common in the forests of a much more moist and tropical可知在上百万年前,北美的森林里面红杉是很容易找到的,选C
小题2:细节题:从文章第二段的句子:It gives the older trees a certain kind of protection from insects,可知树皮的功能是阻止红杉被昆虫侵害,选B
小题3:细节题:从第二段的句子:but the main benefit is that it keeps the center of the tree harmless from moderate forest fires because of its thickness.This fire resistant quality explains why the giant redwood grows to live that long.可知红杉能生长那么久,是因为它能够抵御森林大火的侵害,选C
小题4:细节题:从文章最后一段的句子:When the main tree dies,the shoots are then free to grow as full trees,forming a “fairy ring” of trees around the original tree.These trees,in turn,may give rise to more shoots,and the cycle continues.可知“fairy ring’’ 是通过包围一颗成熟的树形成的,选D
核心考点
试题【Redwood trees are the tallest plants on the earth,reaching heights of up to 100 】;主要考察你对题材分类等知识点的理解。[详细]
举一反三
◆ Timing
The absolutely best time in your life to study abroad is when you are in college. If you miss this opportunity, it’s almost impossible for you to do it later in life.
◆ To gain cross-cultural experience
Life overseas makes you see your everyday world in a whole new light. You don’t even realize it, but our culture shapes the way we view the world and affects us every minute of the day. Differences in culture are more than just differences in language, food, clothing and art.
◆ To improve your communication skills and your self-confidence
People who study abroad tend to be willing to take risks, willing to put themselves in unusual situations, and able to solve problems.
◆ To become more fluent in a language or to learn a new language
The world market is becoming smaller, and many companies require a second language. Foreign languages are not only valuable in the job market but also valuable in the real world.
◆ For the adventure
Travel to other cities within your host country and around neighboring countries. As you get to know your new classmates, roommates, and host family, you will gain a unique view on the host culture. Discover the differences and, more importantly, the many similarities between your worlds. The friendships you make will last long after the program.
◆ To learn more about yourself
Find out who you really are. What are your limits? How do you overcome the difficulties you’ve never encountered before? How independent are you? These questions are hard to answer until you are removed from your usual surroundings. After solving difficult problems on your own overseas, you’ll find that almost nothing will confuse you at home. Students who study abroad commonly report that their study abroad experience actually changed their lives.
小题1:The passage mainly talks about _______.
A.the benefits of studying abroad |
B.the time for studying abroad |
C.the difficulty you come across when you"re abroad |
D.some tips on how to get used to a new environment |
A.When you"re at work. | B.When you are free. |
C.At any time you like. | D.When you are in college. |
A.Opposed. | B.Experienced. | C.Solved. | D.Explained. |
A.getting cross-cultural experience |
B.improving communication skills and self-confidence |
C.improving your foreign language |
D.learning how to get along with people |
Stage 1: Prepare the equipment: a test tube, a crucible, a Bunsen burner and tongs.
Stage 2: Weigh 5 grams of baking soda (sodium bicarbonate) and put it in a crucible.
Stage 3: Heat 10 ml of hydrochloric acid (盐酸) in a test tube.
Stage 4: Pour the warm acid onto the baking soda and continue to heat the mixture.
Result: The acid reacts with the bicarbonate(碳酸氢盐)to form water, carbon dioxide gas and salt. The hotter the mixture, the quicker the reaction. Continue to heat the mixture until the water evaporates, leaving the salt in the crucible.
Paul and his partner followed the instructions and set up their equipment. Paul went to the cupboard to get a bottle of hydrochloric acid. He found that there was only one bottle in the cupboard so he took that. There was no label on the bottle and Paul didn’t check with the teacher if it was the right solution.
He measured the liquid and poured it into a test tube. Using tongs to hold the test tube, he heated it over the Bunsen burner. That’s when things started to go wrong. The liquid in the test tube was not hydrochloric acid. When it was heated, it formed a thick cloud of white gas. Soon the room was full of this strong smelling white gas.
All the students started coughing and their eyes hurt. The teacher immediately opened the windows and ordered the students to leave the laboratory at once. She realized that the liquid was a crylamide (丙烯酰胺) and that it is poisonous.
Fortunately, nobody was injured in the incident. However, it taught the students and the teacher a good lesson.
小题1:What lesson did the incident teach the students and the teacher?
A.Never have a bottle without a label in the chemistry lab! |
B.Obey your teacher’s instructions in the Chemistry lab. |
C.A crylamide can’t take the place of hydrochloric acid. |
D.Finding something unusual happened, you have to leave the laboratory at once. |
A.Water | B.Carbon dioxide gas | C.Salt | D.Poisonous gas |
A.He went to the cupboard to get the bottle by himself. |
B.He found that there was only one bottle in the cupboard so he took that. |
C.There was no label on the bottle. |
D.Paul didn’t check with the teacher that it was the right solution. |
A.Becausethe room was full of this strong smelling white gas. |
B.Because all the students started coughing and their eyes hurt. |
C.Becausethe liquid was a crylamide and that it is poisonous. |
D.Because someone was injured in the incident. |
techniques , but he admitted there would be difficulties in meeting his goal .
“ For example , if you run out of ink while printing on paper , you will throw that paper away . But you cannot throw half-completed buildings away if your material gets stuck , ” he said . Although the printed house is not available to visit , there is a chance for people in Shanghai to see items printed in 3D.
The Belgium-based company Materialise NV held a 3D printing exhibition in Shanghai that started in late 2012 and ended in the middle of 2013 . The company is eager to show Asia what is possible with 3D printing .
“ All the pieces shown here are what cannot be made through traditional techniques . A good example of this customization is hearing aids . More than 10 million people already use 3D printed hearing aids, all made according to the size of their ears , ” said Wim Michiels , executive vice-president at Materialise NV .
“ You can produce anything whenever and wherever you like . You don’t need to set up production lines for pieces that only need a limited amount of products . Setting up a production line is a lot of work . It takes a long time and is very expensive for a limited number of pieces , ” said Michiels .
Kim Francois , managing director of Materialise China , said their European and American clients have already taken the next step toward additive manufacturing with small series production such as hearing aids .
小题1:What is mainly talked about in the text ?
A. The development of 3D printing .
B. A 3D printing show in Shanghai .
C. Varieties of items printed in 3D .
D. The company Materialise NV .
小题2:According to Behrokh Khoshnevis , what is the main difficulty in printing buildings ?
A.Time . | B.Technique . | C.Space . | D.Material . |
A.these items used to be impossible to make |
B.3D printing has a large market share |
C.3D hearing aids help people hear better |
D.people need different sized hearing aids |
A.mass production |
B.making small items |
C.small series production |
D.reducing production costs |
Teaching and learning are two entirely different processes. They differ in kind and function. The function of teaching is to create the conditions and the climate that will make it possible for children to devise the most efficient system for teaching themselves to read. Teaching is also public activity. It can be seen and observed.
Learning to read involves all that each individual does to make sense of the world of printed language. Almost all of it is private, for learning is an occupation of the mind, and that process is not open to public scrutiny.
If teacher and learner roles are not interchangeable, what then can be done through teaching that will aid the child in the quest(探索)for knowledge? Smith has one principal rule for all teaching instructions. “Make learning to read easy, which means making reading a meaningful, enjoyable and frequent experience for children.”
When the roles of teacher and learner are seen for what they are, and when both teacher fulfill them appropriately, then much of the pressure and feeling of failure for both is eliminated. Learning to read is made easier when teachers create an environment where children are given the opportunity to solve the problem of leaning to read by reading.
小题1:The problem with the reading course as mentioned in the first paragraph is that ________.
A.it is one of the most difficult school courses |
B.students spend endless hours in reading |
C.reading tasks are assigned with little guidance |
D.too much time is spent in teaching about reading |
A.teachers can improve conditions at school for the students |
B.teachers can enable students to develop their own way of reading |
C.teachers can devise the most efficient system for reading |
D.teachers can make their teaching activities observable |
A.inquiry | B.observation | C.control | D.suspicion |
A.children become highly motivated |
B.teacher and learner roles are interchangeable |
C.teaching helps children in the search for knowledge |
D.reading enriches children’s experience |
A.teachers should do as little as possible in helping students learn to read |
B.teachers should encourage students to read as widely as possible |
C.reading ability is something acquired rather than taught |
D.reading is more complicated that generally believed |
Beneath the surface of a gemstone, on the tiny level of atoms and molecules(分子), lie clues (线索) to its origin. At this year’s meeting of the Geological Society of America in Minneapolis, Catherine McManus reported on a technique that uses lasers (激光) to clarify these clues and identify a stone’s homeland. McManus directs scientific research at Materialytics, in Killeen, Texas. The company is developing the technique. “With enough data, we could identify which country, which mining place, even the individual mine a gemstone comes from,” McManus told Science News.
Some gemstones, including many diamonds, come from war-torn countries. Sales of those “blood minerals” may encourage violent civil wars where innocent people are injured or killed. In an effort to reduce the trade in blood minerals, the U.S. government passed law in July 2010 that requires companies that sell gemstones to determine the origins of their stones.
To figure out where gemstones come from, McManus and her team focus a powerful laser on a small sample of the gemstone. The technique is called laser-induced breakdown spectroscopy. Just as heat can turn ice into water or water into steam, energy from the laser changes the state of matter of the stone. The laser changes a miniscule part of the gemstone into plasma, a gas state of matter in which tiny particles(微粒)called electrons separate from atoms.
The plasma, which is superhot, produces a light pattern. (The science of analyzing this kind of light pattern is called spectroscopy.) Different elements(元素)produce different patterns, but McManus and her team say that gemstones from the same area produce similar patterns. Materialytics has already collected patterns from thousands of gemstones, including more than 200 from diamonds. They can compare the light pattern from an unknown gemstone to patterns they do know and look for a match. The light pattern acts like a signature, telling the researchers the origin of the gemstone.
In a small test, the laser technique correctly identified the origins of 95 out of every 100 diamonds. For gemstones like emeralds and rubies, the technique proved successful for 98 out of every 100 stones. The scientists need to collect and analyze more samples, including those from war-torn countries, before the tool is ready for commercial use.
Scientists like Barbara Dutrow, a mineralogist from Louisiana State University in Baton Rouge, find the technique exciting. “This is a basic new tool that could provide a better fingerprint of a material from a particular locality,” she told Science News.
小题1:We learn from Paragraph 1 that __________________.
A.an emerald and a ruby are names of diamonds. |
B.it’s not difficult to tell where the gem was mined. |
C.appearances help to identify the origin of gemstones. |
D.diamonds from different places may appear the same. |
A.To look for more gemstones. |
B.To encourage violent civil wars. |
C.To reduce the trade in blood minerals. |
D.To develop the economy. |
A.Heat can turn ice into water or water into steam. |
B.Gemstones from the same area produce similar light patterns. |
C.Laser can changes a miniscule part of the gemstone into plasma. |
D.Materialytics has already collected patterns from thousands of gemstones. |
A.It is ready for commercial use. |
B.People can use the new tool to find more gemstones. |
C.It can significantly reduce the gemstones trade in blood minerals. |
D.It will bring about a revolutionary change in identifying the origin of minerals. |
A.tell us how to identify the origin of diamonds. |
B.introduce a laser technique in identifying a stone’s origin |
C.prove identifying the origin of gemstones are difficult |
D.attract our attention to reducing trade in blood minerals |
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