Format | |
---|---|
Skill | |
Source | |
Topic | |
Test Type | Matching Heading, Matching Information, Multiple choise (1 answer), note/form/sentence completion, Short Answer, T/F/NG |
READING PASSAGE 1
You should spend about 20 minutes on Questions 1-13 which are based on Reading Passage 1 below.
The Pearl
A
The pearl has always had a special status in the rich and powerful all through the history. For instance, women from ancient Rome went to bed with pearls on them, so that they could remind themselves how wealthy they were after waking up. Pearls used to have more commercial value than diamonds until jewellers learnt to cut gems. In the eastern countries like Persia, ground pearl powders could be used as a medicine to cure anything including heart diseases and epilepsy.
B
Pearls can generally be divided into three categories: natural, cultured and imitation. When an irritant (such as a grain of sand) gets. inside a certain type of oyster, mussel, or clam, the mollusc will secrete a fluid as a means of defence to coat the irritant. Gradually, layers are accumulated around the irritant until a lustrous natural pearl is formed.
C
A cultured pearl undergoes the same process. There is only one difference between cultured pearls and natural ones: in cultured pearls, the irritant is a head called ‘mother of pearl’ and is placed in the oyster through surgical implantation. This results in much larger cores in cultivated pearls than those in natural pearls. As long as there are enough layers of nacre (the secreted fluid covering the irritant) to create a gorgeous, gem-quality pearl; the size of the nucleus wouldn’t make a difference to beauty or durability.
D
Pearls can come from both salt and freshwater sources. Typically, pearls from salt water usually have high quality, although several freshwater pearls are considered high in quality, too. In addition, freshwater pearls often have irregular shapes, with a puffed rice appearance. Nevertheless, it is the individual merits that determine the pearl’s value more than the sources of pearls. Saltwater pearl oysters are usually cultivated in protected lagoons or volcanic atolls, while most freshwater cultured pearls sold today come from China. There are a number of options for producing cultured pearls: use fresh water or sea water shells, transplant the graft into the mantle or into the gonad, add a spherical bead or do it nonbeaded.
E
No matter which method is used to get pearls, the process usually takes several years. Mussels must reach a mature age, which may take up almost three years, and then be transplanted an irritant. When the irritant is put in place, it takes approximately another three years for a pearl to reach its full size. Sometimes, the irritant may be rejected. As a result, the pearl may be seriously deformed, or the oyster may directly die from such numerous complications as diseases. At the end of a 5- to 10-year circle, only half of the oysters may have made it through. Among the pearls that are actually produced in the end, only about 5% of them will be high-quality enough for the jewellery makers.
F
Imitation pearls are of another different story. The Island of Mallorca in Spain is renowned for its imitation pearl industry. In most cases, a bead is dipped into a solution made from fish scales. But this coating is quite thin and often wears off. One way to distinguish the imitation pearls is to have a bite on it. Fake pearls glide through your teeth, while the layers of nacre on the real pearls feel gritty.
G
Several factors are taken into account to evaluate a pearl: size, shape, Colour, the quality of surface and luster. Generally, the three types of pearls come in such order (with the value decreasing): natural pearls, cultured pearls and imitation pearls (which basically are worthless). For jewellers, one way to tell whether a pearl is natural or cultured is to send it to a gem lab and perform an X-ray on it. High-quality natural pearls are extremely rare. Japan’s Akoya pearls are one of the glossiest pearls out there, while the’ south sea water of Australia is a cradle to bigger pearls.
H
Historically, the pearls with the highest quality around the globe are found in the Persian Gulf, particularly around Bahrain. These pearls have to be hand-harvested by divers with no advanced equipment. Unfortunately, when the large reserve of oil was discovered in the early 1930s, Persian Gulf’s natural pearl industry came to a sudden end because the contaminated water destroyed the once pristine pearls. In the present days, India probably has the largest stock of natural pearls. However, it is quite an irony that a large part of India’s slock of natural pearls are originally from Bahrain.
READING PASSAGE 2
You should spend about 20 minutes on Questions 14-27 which are based on Reading Passage 2 below.
The start of the automobile’s history went all the way back to 1769 when automobiles running on the steam engine were invented as carriers for human transport. In 1806, the first batch of cars powered by an internal combustion engine came into being, which pioneered the introduction of the widespread modem petrol-fueled internal combustion engine in 1885.
It is generally acknowledged that the first practical automobiles equipped with petrol/gaso-line-powered internal combustion engines were invented almost at the same time by different German inventors who were Working on their own. Karl Benz first built the automobile in 1885 in Mannheim. Benz attained a patent for his invention on 29 January 1886, and in 1888, he started to produce automobiles in a company that later became the renowned Mercedes-Benz.
As this century began, the automobile industry marched into the transportation market for the wealth. Drivers at that time were an adventurous bunch; they would go out regardless of the weather condition even if they weren’t even protected by an enclosed body or a convertible top. Everybody in the community knew who owned what car, and cars immediately became a symbol of identity and status. Later, cars became more popular among the public since it allowed people to travel whenever and wherever they wanted. Thus, the price of automobiles in Europe and North America kept dropping, and more people from the middle class could afford them. This was especially attributed to Henry Ford who did two crucial things. First, he set the price as reasonable as possible for his cars; second, he paid his employees enough salaries so that they could afford the cars made by their very own hands.
The trend of interchangeable parts and mass production in an assembly line style had been led by America, and from 1914, this concept was significantly reinforced by Henry Ford. This large-scale, production-line manufacture of affordable automobiles was debuted. A Ford car would come off all assembled from the line every 15 minutes, an interval shorter than any of the former methods. Not only did it raise productivity, but also cut down on the requirement for manpower. Ford significantly lowered the chance of injury by carrying out complicated safety procedures in production—particularly assigning workers to specific locations rather than giving them the freedom to wander around. This mixture of high wages and high efficiency was known as Fordism, which provided a valuable lesson for most major industries.
The first Jeep automobile that came out as the prototype Bantam BRC was the primary light 4-wheel-drive automobile of the U.S. Army and Allies, and during World War II and the postwar period, its sale skyrocketed. Since then, plenty of Jeep derivatives with similar military and civilian functions have been created and kept upgraded in terms of overall performance in other nations.
Through all the 1950s, engine power and automobile rates grew higher, designs evolved into a more integrated and artful form, and cars were spreading globally. In the 1960s, the landscape changed as Detroit was confronted with foreign competition. The European manufacturers, used the latest technology, and Japan came into the picture as a dedicated car-making country. General Motors, Chrysler, and Ford dabbled with radical tiny cars such as the GM A-bodies with little success. As joint ventures such as the British Motor Corporation unified the market, captive imports and badge imports swept all over the US and the UK. BMC first launched a revolutionary space-friendly Mini in 1959, which turned out to harvest large global sales. Previously remaining under the Austin and Morris names, Mini later became an individual marque in 1969. The trend of corporate consolidation landed in Italy when niche makers such as Maserati, Ferrari, and Lancia were bought by larger enterprises. By the end of the 20th century, there had been a sharp fall in the number of automobile marques.
In the US, car performance dominated marketing, justified by the typical cases of pony cars and muscle cars. However, in the 1970s, everything changed as the American automobile industry suffered from the 1973 oil crisis, competition with Japanese and European imports, automobile emission-control regulations* and moribund innovation. The irony in all this was that full-size sedans such as Cadillac and Lincoln scored a huge comeback between the years of economic crisis.
In terms of technology, the most mentionable developments that postwar era had seen were the widespread use of independent suspensions, broader application of fuel injection, and a growing emphasis on safety in automobile design. Mazda achieved many triumphs with its engine firstly installed in the fore-wheel, though it gained itself a reputation as a gas-guzzler.
The modem era also has witnessed a sharp elevation of fuel power in the modem engine management system with the. help of the computer. Nowadays, most automobiles in use are powered by an internal combustion engine, fueled by gasoline or diesel. Toxic gas from both fuels is known to pollute the air and is responsible for climate change as well as global warming.
READING PASSAGE 3
You should spend about 20 minutes on Questions 28-40 which are based on Reading Passage 3 below.
Elephant communication
A
A postdoctoral fellow at Stanford University, O’Connell-Rodwell has come to Namibia’s premiere wildlife sanctuary to explore the mysterious and complex world of elephant communication. She and her colleagues are part of a scientific revolution that began nearly two decades ago with the stunning revelation that elephants communicate over long distances using low-frequency sounds, also called infrasounds, that are too deep to be heard by most humans.
B
As might be expected, the African elephant’s ability to sense seismic sound may begin in the ears. The hammer bone of the elephant’s inner ear is proportionally very large for a mammal, buy typical for animals that use vibrational signals. It may, therefore, be a sign that elephants can communicate with seismic sounds. Also, the elephant and its relative the manatee are unique among mammals in having reverted to a reptilian-like cochlear structure in the inner ear. The cochlea of reptiles facilitates a keen sensitivity to vibrations and may do the same in elephants.
C
But other aspects of elephant anatomy also support that ability. First, their enormous bodies, which allow them to generate low-frequency sounds almost as powerful as those of a jet takeoff, provide ideal frames for receiving ground vibrations and conducting them to the inner ear. Second, the elephant’s toe bones rest on a fatty pad that might help focus vibrations from the ground into the bone. Finally, the elephant’s enormous brain lies in the cranial cavity behind the eyes in line with the auditory canal. The front of the skull is riddled with sinus cavities that may function as resonating chambers for vibrations from the ground.
D
How the elephants sense these vibrations is still unknown, but O’Connell-Rodwell who just earned a graduate degree in entomology at the University of Hawaii at Manoa, suspects the pachyderms are “listening” with their trunks and feet. The trunk may be the most versatile appendage in nature. Its uses include drinking, bathing, smelling, feeding and scratching. Both trunk and feet contain two kinds of pressure-sensitive nerve endings – one that detects infrasonic vibrations and another that responds to vibrations with slightly higher frequencies. For O’Connell-Rodwell, the future of the research is boundless and unpredictable: “Our work is really at the interface of geophysics, neurophysiology and ecology,” she says. “We’re asking questions that no one has really dealt with before.”
E
Scientists have long known that seismic communication is common in small animals, including spiders, scorpions, insects and a number of vertebrate species such as white-lipped frogs, blind mole rats, kangaroo rats and golden moles. They also have found evidence of seismic sensitivity in elephant seals – 2-ton marine mammals that are not related to elephants. But O’Connell-Rodwell was the first to suggest that a large land animal also is sending and receiving seismic messages. O’Connell-Rodwell noticed something about the freezing behavior of Etosha’s six-ton bulls that reminded her of the tiny insects back in her lab. “I did my masters thesis on seismic communication in planthoppers,” she says. “I’d put a male planthopper on a stem and playback a female call, and the male would do the same thing the elephants were doing: He would freeze, then press down on his legs, go forward a little bit, then freeze again. It was just so fascinating to me, and it’s what got me to think, maybe there’s something else going on other than acoustic communication.”
F
Scientists have determined that an elephant’s ability to communicate over long distances is essential for its survival, particularly in a place like Etosha, where more than 2,400 savanna elephants range over an area larger than New Jersey. The difficulty of finding a mate in this vast wilderness is compounded by elephant reproductive biology. Females breed only when in estrus – a period of sexual arousal that occurs every two years and lasts just a few days. “Females in estrus make these very low, long calls that bulls home in on, because it’s such a rare event,” O’Connell-Rodwell says. These powerful estrus calls carry more than two miles in the air and may be accompanied by long-distance seismic signals, she adds. Breeding herds also use low-frequency vocalizations to warn of predators. Adult bulls and cows have no enemies, except for humans, but young elephants are susceptible to attacks by lions and hyenas. When a predator appears, older members of the herd emit intense warning calls that prompt the rest of the herd to clump together for protection, then flee. In 1994, O’Connell-Rodwell recorded the dramatic cries of a breeding herd threatened by lions at Mushara. “The elephants got really scared, and the matriarch made these very powerful warning calls, and then the herd took off screaming and trumpeting,” she recalls. “Since then, every time we’ve played that particular call at the water hole, we get the same response – the elephants take off.”
G
Reacting to a warning call played in the air is one thing, but could the elephants detect calls transmitted only through the ground? To find out, the research team in 2002 devised an experiment using electronic equipment that allowed them to send signals through the ground at Mushara. The results of our 2002 study showed us that elephants do indeed detect warning calls played through the ground,” O’Connell-Rodwell observes. “We expected them to clump up into tight groups and leave the area, and that’s in fact what they did. But since we only played back one type of call, we couldn’t really say whether they were interpreting it correctly. Maybe they thought it was a vehicle or something strange instead of a predator warning.”
H
An experiment last year was designed to solve that problem by using three different recordings – the 1994 warning call from Mushara, an anti-predator call recorded by scientist Joyce Poole in Kenya and an artificial warble tone. Although still analyzing data from this experiment, O’Connell-Rodwell is able to make a few preliminary observations: “The data I’ve seen so far suggest that the elephants were responding as I had expected. When the ’94 warning call was played back, they tended to clump together and leave the water hole sooner. But what’s really interesting is that the unfamiliar anti-predator call from Kenya also caused them to clump up, get nervous and aggressively rumble – but they didn’t necessarily leave. I didn’t think it was going to be that clear cut.”
AIM8IELTS.com được thành lập với mục tiêu trở thành cộng đồng uy tín cung cấp tài liệu, công cụ luyện tập và kiến thức cho các sĩ tử đang luyện thi IELTS từ 0-8.0IELTS
Disclaimer:
This disclaimer shall govern your use of our website (www.aim8ielts.com) and by using this website, you accept this disclaimer in full.
IELTS® is a registered trademark of the British Council, IDP: IELTS Australia and Cambridge English Language Assessment and they jointly manage the IELTS test.
By using this website, you agree that you fully understand that AIM 8 IELTS and this website – www.aim8ielts.com – have no affiliation, approval or endorsement by any IELTS owner. The purpose of this website, and all the resources provided here, is to help you improve your English for the IELTS test.
Copyright © AIM8IELTS All rights reserved Copyrights 2023
Cô Huyền sẽ liên hệ trực tiếp với bạn qua email hoặc điện thoại trong 1-2 ngày tới để trao đổi cụ thể hơn về việc học.
Hoặc bạn cũng có thể chủ động liên hệ với cô giáo theo thông tin dưới đây để được xếp lớp sớm nhất.
Email: huyenbui@cohuyenielts.com
Xin cám ơn.
Để đăng ký học IELTS lớp cô Huyền, vui lòng điền form dưới đây để được tư vấn. Hoặc gọi điện trực tiếp cho cô giáo theo số +84.0383.096.717 để giữ chỗ.
Để đăng ký nhanh nhất, vui lòng liên hệ trực tiếp cho cô Huyền theo số:
Email: huyenbui@cohuyenielts.com
Địa chỉ: 63 Vũ Ngọc Phan, Láng Hạ, Đống Đa, Hà Nội