Tree Rings

Do you know something about tree rings? Do you know they can tell us what the weather was like, sometimes they can show us an exact record of the weather even hundreds of years ago. A tree will grow well in a climate with lots of sunlight and rainfall. It is also expected that little sunlight or rainfall will limit the growth of a tree. The change from a favorable to an unfavorable climate can be seen by reading the tree ringsin a tree trunk.To find out the w eather of tenyears ago,countthe r…     

短文改错

A person s age no longer tells you som ething about1.his socialposition,marriage or healthy.There s no longer2.ooldena particular year which one goes to school or goes to3.work or gets m arried or start a fam ily.The socialclock4.thatkeptus on tim e and told us w hen go to school,get5.a job,or stop w orking isn t as strong as itwas used to be.6.It doesn tsurprise us to hear a28-year-old university7.presidentor a35-year-old grandm other,or70-year-old8.m an w ho has becom e a father for the firs…     

情态动词专练(英文)

1.Y ou didn t go to the party yesterday,or I you.A .would see B .could seeC.m ighthave seen D .m ightsee2.—W hat itbe?—It be a car,for it is notm oving.It be a house.A .can;can t;m ust B .m ust;m ustn t;canC.can;can;m ust D .can;m ustn t;m ust3.There w as plenty of tim e.She .A .m ustn t have hurried B .couldn t have hurriedC.m ustn t hurry D .needn t have hurried4.W hen he w as there,he go to that coffee shop at the corner afterwork every day.A .would B .should C .had better D .m ig…     

Bearing capacity of composite columns reinforced by concrete filled steel tube

In this study, nine simplified short composite columns consisting of core CFST (concrete filled steel tube) of different diameters and outer reinforced concrete were constructed to study their compressive performance under axial or eccentric compression. The failure mode is characterized by the crush of the outer concrete. The bearing capacity increases at first and then decreases with further increase of the position coefficient. It can be concluded that position coefficient is an important structural parameter that has considerable influences on the ultimate bearing capacity of the composite columns. The outer concrete, steel tubes and longitudinal reinforcement are found to work in a cooperative manner under axial or eccentric compression when the position coefficient is about 0.5. An improved bearing capacity algorithm that takes the position coefficient into account has been proposed based on the experimental and simulation results and current technical specification in China. It has been proven to be precise and safe.     

I really like this sentence

I really like this sentence: T he choic- es you m ake and the w ay you live now w illdeterm ine w hat your future w illbe. I can learn a lot of things from this sentence. N ow everybody in our class is a student. B ut after 20 years, w hat w ill they be like? N obody know s. I read a story recently. It w as interesting. It is about som eone m any years ago. H e know s w hat his future w ill be like and he is very w orried about it. E very tim ew hen he begins to w ork, he w ould think about…     

笑话五则(英文)

M ore Polite A fat m an and a skinny m an were arguing about who was the m ore polite.The skinny m an said he w as m ore polite because he alw ays tipped (轻拿)his hat to ladies.But the fat m an said he was the m ore courteous of the tw o because,whenever…     

A non-canonical example to support P is not equal to NP

The more unambiguous statement of the P versus NP problem and the judgement of its hardness, are the key ways to find the full proof of the P versus NP problem. There are two sub-problems in the P versus NP problem. The first is the classifications of different mathematical problems (languages), and the second is the distinction between a non-deterministic Turing machine (NTM) and a deterministic Turing machine (DTM). The process of an NTM can be a power set of the corresponding DTM, which proves that the states of an NTM can be a power set of the corresponding DTM. If combining this viewpoint with Cantor’s theorem, it is shown that an NTM is not equipotent to a DTM. This means that "generating the power set P(A) of a set A" is a non-canonical example to support that P is not equal to NP.     

Telephone

A lexander Bellw as an A m erican scientist.H e m ade the firsttelephone in 1876.Bell w as born in Scotland in 1847. Bellfound a job in the U nited States.H e w orked asateacherin a new schoolforthe deaf.H e liked tohelp the deaf.H e tried to find a w ay to send avoice overw ires.Bellthoughtthatspoken w ords w ere m adeup of different vibrations. H e thought that if aw ire could carry vibrations,itcould surely carrya m an’svoice.Bellkeptw orking atit.H isassis-tantw orked w ith him forne…     

阅读理解精练

There are people in Italy w ho can’t stand soccer. N ot a11 Canadians love hockey.A sim ilar situation exists in A m er- ica, where there are those people you m ay be one of them who yawn or even frow n(皱 眉 头 ) when som ebody m entions baseball. Baseball to them m eans boring hours watching grow n m en in funny tight outfits standing around in a field staring away while very little of anything happens. They tell you it’s a gam e better suited to the 19th century, slow, quiet, gentlem an…     

I''''M ORLONSEL SIMPSON!

The persona of this story was a boy in a gutter(贫民区)of San Francisco.Because of cacotrophia(营养不良),he got sick with his leg.H e couldn’t stand with his legstraight.A nd his calf(小腿)was even worse shrink(萎缩).But in his little soul,he got a dream only believed byhim self—he would becom e an all-powerful(全能的)playerof A m erican football.The boy was a fan of Jim Brown,a legendary foot-ball player.H e always went to the court to cheer his i-dol.But he was too poor to buy a ticket…     

On Translation of Images in English Poems——in Virtue of the Dynamic Equivalence Theory

Image is not only an essential part,but also a major means to convey the implications in English poems.It is a literal and concrete representation of a sensory experience of an object.The rendering of images in English poems into Chinese can be guided by the dynamic equivalent translation theory put forward by Dr.Eugene A Nida.The theory emphasizes the roughly equivalent response of the target language receptors to the TL text to that of the source language receptors to the SL text.To achieve a Dynamic Equivalence,methods like Direct Translation,Addition,and Substitution can be employed in the translation of images in English poems.     

Schools in the Future

Som e people believe that schools w ill no longer be necessary in thenear future.They say thatbecause of the Internet and other new technolo-gy,there is no longer any need for school buildings,classes or teachers.Perhaps this willbe true one day,but ifthe world has no schools,I can tim agine how our society w ill be.In fact,w e should learn how to use newtechnology to m ake schools better.W e should invent a new kind of schoolthat is linked(链 接)to libraries,m useum s,science centres,labs an…     

完形填空解析一则

I spent two m onths with an A m ericanfam ily last year when I studied in A m erica.It is said,“The best house is in A m erica,the best w ife is in Japan,and the best food isin C hina.”So I took pride and1to2“the best food”for m y A m erican fam-ily.E ach day,regardless of m y poor skill ofcooking,I would do som ething in3w ay:changing the dishes colour,the m eat’s type orthe soup’s style(风味).Thus,m y A m ericanfriends could discover the4of eatingC hinese food.Because of m y“5”job,Iw as often rew arded(奖励)b...     

The Door

The door was about six-and-a-half feet by three feet. Mahogany, painted black.It stood between Tom and a world of new adventures and an unforeseeable future. It was the gate of judgment, the way to Heaven or to Hell.     

笑话四则(英文)

A T alk about G eniusPatient:D octor,is genius a kind ofdisease?D octor:If so,you needn t w orry about it.Y ou do not have this kindofdisease definitely.A B ow land a C atA m an was looking for ancient objects.O ne day he cam e to a villageand found a bow lthatlooked very old.The bowl was lying on the groundand a cat was drinking m ilk from it.In order not to draw the attention of the farm er w ho had the bow l tothe value of the bow l,the m an said to him in a casual voice:“W hat anice …     

Relations and Operations of Sets

If A and B are two sets,A is said to be a subsetof B if and only if every element of A is also anelement of B.The subset relation is indicated by thesymbolismAB(or BA)which is read“A is a subset of B”or“A is includedin B”or“B includes A”.It is clear from the definition that every set A isa subset of itself.It is important to know that theempty setis the subset of any set A:A.(Wewill explain it in the logic part)Two sets A and B are said to be equal if and     

Task-and-role-based access-control model for computational grid

Access control in a grid environment is a challenging issue because the heterogeneous nature and independent administration of geographically dispersed resources in grid require access control to use fine-grained policies. We established a task-and-role-based access-control model for computational grid (CG-TRBAC model), integrating the concepts of role-based access control (RBAC) and task-based access control (TBAC). In this model, condition restrictions are defined and concepts specifically tailored to Workflow Management System are simplified or omitted so that role assignment and security administration fit computational grid better than traditional models; permissions are mutable with the task status and system variables, and can be dynamically controlled. The CG-TRBAC model is proved flexible and extendible. It can implement different control policies. It embodies the security principle of least privilege and executes active dynamic authorization. A task attribute can be extended to satisfy different requirements in a real grid system.     

Introduction to the F. L. T. Terms

Needs Analysis An investigation, in the light of aspecification of the tasks a learner or group of learners will berequired to perform in the TL, of what particular aspects of theTL need to be learnt in order to bring about proficiency in theseparticular tasks. The results of the needs analysis can then beused to determine a syllabus and suitable teaching techniques. Norm(ⅰ) The mode of speech and the grammatical us     

Effect of Foam Cladding for Blast Mitigation:Numerical Simulation

Two numerical simulations were performed to investigate the protective effect of the foam cladding. One simulation is based on a previous experimental study, which is a ballistic pendulum with and without a foam cladding subjected to close-range blast loading. The other model is a steel beam with and without a foam cladding under blast loading. The overpressure due to the blast event can be calculated by the empirical function ConWep or by an arbitrary Lagrangian-Eulerian (ALE) coupling model. The first approach is relatively simple and widely used. The second approach can model the propagation of the blast wave in the air and the interaction between the air and the solid. It is found that the pendulum with the foam cladding always swings to a larger rotation angel compared to a bare pendulum. However, the steel beam with an appropriate foam cladding has a smaller deflection compared to the bare beam without a foam cladding. It is concluded that the protective effect of the foam cladding depends on the properties of the foam and the protected structure.     

牧羊人、老虎与狐狸

A shepherd brought his sheep into the field to graze, and sat downunder a tree to rest.Suddenly a tiger cam e outofthe w oods.The shepherd picked up his staffand jum ped up.The tiger w as just about to spring at the m an when he saw the staffand got frightened. The tiger thought it was a gun. They stared at eachother,and neither dared to m ake the first m ove.A t that m om ent, a fox cam e running by. The fox saw that the tigerand the shepherd were afraid of each other and decided to turn th…