In a unique study, researchers at Land University in Sweden have mapped the origins of migratory bird. They used the results to investigate and discover major differences in the immune systems of sedentary and migratory birds. The researchers conclude that migratory species benefit from leaving tropical areas when it is time to rise their young - as moving away from disease in the tropics enables them to survive with a less costly immune system. Analysing the geneoalogy of over 1 ,300 song bird species, passerines, enabled the researchers to establish that both sedentary birds, which do not leave nothern Europe in the winter, and migratory bird, which breed in Europe but spend the winter close to the equator, originate from Africa. The researchers then went on to study the immune system in three different groups: sedentary birds in tropical Africa, European sedentary birds, and migratory bird. Their findings show that African sedentary birds have a more varied and extensive immune system than that of both European sedentary birds and migratory birds. Evolution has quite simply ensured that bird specues migrating to Europe were equipped with a much less variable immune system, as Europe has far fewer diseaes that the tropics. The African sedentary species probably need a more advanced immune system to deal with the richer flore of pathogens to which they are exposed. What really surprised the researchers was that the immune system of migratory birds showed similarity low variation to that of European sedentary birds. After all, migratory birds do not only need to resist diseases in Europe, but alo during their migration and in the tropic. To explain the surprising result, the researchers propose the idea that the costs associated with a strong and complex immune system could be much higher than anyone previously thought. Examples of these costs could be autoimmunity and other immune system diseases such as chronic imflammation. Despite the migratory birds having to deal with pathogens both in Europe and tropical Africa, they have thus lost much of the variation and complexity in their immune system compared to their African ancestors. According to the researchers, this indicates that deal ing with pathogens is the most difficult for the birds the first time they are exposed to them. For migratory birds, this happens in Europe where they rise their young and there are not as many different pathogens. One of the researchers explained that when the migratory birds bred, they had moved away from many diseases and therefore did not need an immune system that was equally varied. Another dvantage was that the risk of damage caused by the immune system dropped considerably if the immune system was less complex. All vertebrates, including human beings, have an immune system built up in a similar way to that of birds. The Lund biologists therefore believe that their findings could also be significant in a broader perspective. Adapted from https//www .sciencedaily .com/releases/20 1 8/04/1 8041 01 03507 .htm It is implied in paragraph two that (A) migratory birds tend to stay longer near the equator. (B) European and African sedentary birds are of the same species. (C) European sedentary birds return to Africa to raise their young. (D) European sedentary birds fly over the equator. (E) migratory birds live near the equator before they move and breed.

Whether it's the melodic sound of an Eric Clapton solo or the growl of a heavy metal band, the electric guitar has influenced popular music and culture more than any other instrument. Rock's greatest musicians have always been closely identified with their guitars. But instruments being designed for tomorrow's pop stars may look and sound rather different from today's familiar electric and acoustic guitars. Since the time when the electric guitar was invented, there have been incredible changes to the technical design of the instrument. From what was once a rounded wooden box with a hole in the front, the guitar has evolved into the smooth solid body of the rock guitarist's 'axe'. The most modern guitars are really computercontrolled synthesizers. Adolph Rickebacker's Electro String Company produced the world's first electric guitar. It was made of wood and played on the user's lap. The first real breakthrough in design came in 1950 when Leo Fender, a Californian radio repairman, made the first solid-bodied electric guitar, the Fender Telecaster. Soon after the inventor Les Paul made the famous Gibson Les Paul. Fender launched its stylish Stratocaster two years later. The guitars became standard instruments against which newer guitar designs are measured. All sorts of dift:erent materials have been used to make guitars. Acoustic guitars are made from wood, which gives a soft tone. Wood is also a popular material in electric guitar manufacture, but more modern materials such as glass and carbon fiber are also used. There have also been guitars with metal bodies and necks though these were never popular with players, who claim metal feels cold in the hand. Plastics, on the other hand, have been more used in guitar bodies. A company that makes parts for the aerospace industry has begun to use a kind of fiberglass that was originally used in helicopter blades to make the bodies for its electric-acoustic instruments. As long as scientists and musicians work together harmoniously, the electric guitar will continue to benefit from technological innovations. But for all the efforts of the guitar companies' design engineers, production managers and quality controller, it's the musicians who finally make the instruments sing- and not necessarily in the way the guitar maker intended. From the text we may conclude that ... (A) wood remains the best material for making guitars (B) guitar materials control the type of music the musicians play (C) technology has played a significant role in the design and development of guitars (D) today's designs are not very much different from those of the past (E) the use of fiberglass in aeroplanes was inspired by guitar makers

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Everyone likes to group things. Language students group word as verbs, nouns and so on; collections of words are classified as phrases, or clauses, or sentences, and these again are reclassified according to their function. In the same way, botanistsw classify plants as algae, or fungi, or gymnosperms, etc. Zoologysts classify animals as vertrebrates and investibrates. The vetrebrates can be further classified as mammals, reptiler, birds, fish, etc. Classification enables us to keep hold of more information and, if it is based on the right data, enables us to understand better the ideas we are studying. Chemists are no exception. The chemical classification of materials, if it is based on a good system, should enable us to understand better the many substances which exist in our word. What is to be the basis of our classification? Perhaps the most obvious one is appearance. Materials could be classified as solid, liquid or gas with some mixed types as, for example, mud being solid/liquid material and steam a liquid/gas material. Appearance could enable us to subdivide our main classification groups a little further; the solid may be green, or black, powdery or crystalline; the liquid may be colored, oily, thick, or free flowing; the gas may be colored. However, we soon realize that many probably quite different materials have the same appearance. Both air and the deadly carbon-monoxide gas, are colorless, odorless gases, but we would not like to group them as the same thing. Many different liquids are colorless, water-like materials. Paragraph 2 exemplifies the idea about classification that ... . A. chemicals may be solid, liquid, and gaseous. B. Appearance is not a useful basis in chemistry. C. The use of colors is better than that of appearance. D. Both colors and appearance should be considered E. Colors should be included for identifying appearance.

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The word gambut (peat) is taken from the name of a village, Desa Gambut (now Garnbut sub-district), which is located about 10 km east of Banjarmasin, South Kalimantan. It is at this place that for the first time, rice has been successfully cultivated in peat soiled rice fields. In the soil taxonomy system, peat soils are grouped into a separate soil order called hisiosols, which means that the land is predominantly composed of organic soil materials in the form of remains of plant tissues. The nature and the characteristics of peat soils can be determined based on their physical and chemical properties. Gambut has dark brown to blackish colors. Although its basic materials are gray, brown or reddish, after decomposition, the dark humid compounds will appear. Furthermore, based on the weight of the contents, peat soil or gambut, which has undergone further decomposition, has a content weight ranging from 0.2 to 0 3 g cm2. Due to the low content weight, peat has a large capacity-as water storage about 2-4 times its dry weight. In fact, moss peat that has not decomposed can store up to 12 or 15 even 20 times more water than its own weight. In addition, peat soil has a large absorption area, which is up to 4 times greater than montmorillonite clay. Next, peat soil has acidic reaction properties. Decomposition of organic matters will produce organic acids that accumulate in the bodv of the soil hence increasing the acidity of the peat soil. Generally, peat soil shows real resistance to changes in pH when compared to mineral soils. As a result, peat soil requires more limestone to increase the pH at the same level of the value of mineral soil. Thus, peat soil requires a higher dose of fertilizers than mineral soil. Furthermore, based on the nutrients contained in it, peal soil is a type of nutrient-poor soil. High levels of N and organic matters in peat soils are also accompanied by a high N nitrification process so that the activity of heterotrophic organisms is not well stimulated and the organisms active in the nitrification process can carry out (heir activities. Therefore, the levels of P (phosphorus) and K (potassium) of peat soils are generally lower than that of the mineral soils. Also, the plants cultivated on the peat soil are very responsive to the fertilization using P and K. (adapted fiom hilps://freelearningji.wordpress.com} The phrase * large capacity as water storage* in paragraph 2 can be replaced by ... A. Power to withstand heavy water currents B. Capacity to keep water flowing stable C. High quality and quantity of water D. Potential to make large water storage E. Ability to deposit a large amount of water

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Many modern educational experts claim that teaching facts and academic skills is less important than achieving other social objectives. For some liberals, the schools must first change attitudes or provide nurturing in place of failed families or help establish equality and social justice. For some conservatives, the school must first prepare kids for the workplace by molding them into supple corporate citizens, while others want the focus to be on family values, a competitive spirit, or other social or behavioral objectives. But the idea of simply educating kids seems to have taken a backseat to most educational experts and administrators. They miss the point that kids with real academic skills, especially skills in reading, writing, and mathematics, are more likely to overcome social barriers, more likely to have genuine self esteem, and most likely to be genuinely prepared for the challenges of life and the workplace. By emphasizing so many things besides a genuine, classical education, tile educational establishment tends to soli our kids short and bring about many of the problems they claim to be solving. Consider the case of Wesley Elemontary School in Houston. According to Richard Nadlor in the article, "Failing Grade", Wesley has all the demographic markers of a school bound for failure. Over 80% of the students qualify for subsidized lunches, and nearly all are minorities (92% black, 7% Hispanic). Yet it ranks among the best schools of Houston, with first-graders placing at the 82nd percentile level in reading tests which is 50 points higher than the expected level for similar at-risk schools. What has made Wesley so successful? The answer is classical education in the form of Direct Instruction curriculum designed by Siegfried Engelmann, an example of the much ridiculed "sage-onthe-stage" approach. This Direct Instruction system boosts reading, writing, and math scores by 30 to 40 percentile points in at-risk schools. Sadly, Engelmann, like others who successfully challenge popular fads in educational reform, has been rejected by much of the educational establishment. His success is an embarrassment to them. Given the baseline score in reading is 23 percentile points, which of the following most likely reflects the maximum impact of Direct Instruction on the students learning achievement in Wesley Elementary School? A. 45 B. 53 C. 63 D. 85 E 95

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bagaimana cara kita supaya bisa menggunakan bahasa Inggris dengan waktu yg cepat??

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