- Câu hỏi 738348:
Read the text and choose the best answer.
In the 1940's and 1950's, biochemists strived to learn why each of the vitamins was essential for health. They discovered that key enzymes in metabolism depend on one or another of the vitamins as coenzymes to perform the chemistry that provides cells with energy for growth and function. Now, these enzyme hunters occupied center stage.
The word "strived" is closest in meaning to
A. experimented
B. tried
C. failed
D. studied
- Câu hỏi 738351:
Read the text and Decide that the following statements are TRUE (T), FALSE (F) or NOT GIVEN (NG).
Anyone can set up a site; promoting your club, your institution, your company's products or simply yourself, is what the Web and the Internet is all about. And what is more, information on the Internet is not owned or controlled by anyone organisation. It is, perhaps, true to say that no-one and therefore everyone owns the 'Net'. Because of the relative freedom of access to information, the Internet has often been criticised by the media as a potentially hazardous tool in the hands of young computer users. This perception has proved to be largely false however, and the vast majority of users both young and old get connected with the Internet for the dual purposes for which it was intended – discovery and delight.
According to the author, the Information Superhighway may be the future hope of education.
- Câu hỏi 6945:
Read the text and answer the question.
Barack Obama was as surprised as most of America, and much of the world, when he was woken up and told he had won the Nobel Peace Prize after just nine months as president and while he is still deciding whether to escalate the war in Afghanistan. The Nobel Committee said it chose Obama “for his extraordinary efforts to strengthen international diplomacy and cooperation between peoples” and for creating “a new international climate”.
How long had Barack Obama been US president when he was awarded the Nobel Peace Prize?
A. eight months
B. nine months
C. three months
D. five months
- Câu hỏi 113841:
Read the text and choose the best answer.
A monarchy is a form of government where a single ruler is the head of state. It is one of the oldest forms of government in the world. Monarchs are usually kings or queens. But they can also be a chief, an emperor, or called by another name. In some countries, such as , the monarch is merely symbolic. They are figureheads with no real power. In other countries, the monarch wields considerable power. There are currently 29 sovereign monarchies around the world.
Hereditary monarchy is the most common style of succession. This form is used by most of the world's monarchies. In this case, all of the kings and queens come from the same family. A family that rules for a span of time is called a dynasty. The crown is passed down from one member to another member of the family. The hereditary system has the advantages of stability, continuity, and predictability. Family affection and loyalty are also stabilizing factors.
According to the passage, hereditary monarchy is
A. a form of absolute monarchy
B. a figurehead position
C. the most common style of succession
D. also called a tsar
- Câu hỏi 113846:
Read the text and choose the best answer.
The first two decades of this century were dominated by the microbe hunters. These hunters had tracked down one after another of the microbes responsible for the most dreaded scourges of many centuries: tuberculosis, cholera, diphtheria. But there remained some terrible diseases for which no microbe could be incriminated: scurvy, pellagra, rickets, beriberi. Then it was discovered that these diseases were caused by the lack of vitamins, a trace substance in the diet. The diseases could be prevented or cured by consuming foods that contained the vitamins. And so in the decades of the 1920's and 1930's, nutrition became a science and the vitamin hunters replaced the microbe hunters.
In the 1940's and 1950's, biochemists strived to learn why each of the vitamins was essential for health. They discovered that key enzymes in metabolism depend on one or another of the vitamins as coenzymes to perform the chemistry that provides cells with energy for growth and function. Now, these enzyme hunters occupied center stage.
You are aware that the enzyme hunters have been replaced by a new breed of hunters who are tracking genes-the blueprints for each of the enzymes-and are discovering the defective genes that cause inherited diseases-diabetes, cystic fibrosis. These gene hunters, or genetic engineers, use recombinant DNA technology to identify and clone genes and introduce them into bacterial cells and plants to create factories for the massive production of hormones and vaccines for medicine and for better crops for agriculture. Biotechnology has become a multibillion-dollar industry.
In view of the inexorable progress in science, we can expect that the gene hunters will be replaced in the spotlight. When and by whom? Which kind of hunter will dominate the scene in the last decade of our waning century and in the early decades of the next? I wonder whether the hunters who will occupy the spotlight will be neurobiologists who apply the techniques of the enzyme and gene hunters to the functions of the brain. What to call them? The head hunters. I will return to them later.
What is the main topic of the passage?
A. The progress of modern medical research
B. The discovery of enzymes
C. The potential of genetic engineering
D. The microbe hunters
- Câu hỏi 113851:
Read the text and decide that the statement is True (T), False (F) or Not Given (NG).
In the 18th century, too, many new buildings were constructed. It was a prosperous period, when the new aristocracy paid for splendid buildings, banquets and balls, not to mention the latest fashions from Europe.
The rise of Napoleon in the early 19th century led to political changes throughout Europe. An uprising took place in Mexico in l810, with the aim of ending rule from Spain. This goal was finally achieved in 1821, when Mexico City briefly became the capital of the Mexican Empire. Since 1823, it has been the capital of the Republic of Mexico, apart from a short period, from 1863 to 1867, when the country was again an empire.
Spanish rule of Mexico ended in 1810.
- Câu hỏi 113854:
Read the text and choose the best answer.
Many young people from disadvantaged social classes join gangs. Gangs are groups of individuals who share a common identity. Some anthropologists believe the gang structure is one of the most ancient forms of human organization. Gangs are often associated with criminal activities.
Street gangs tend to be populated with young people from low income or impoverished homes. In contrast, organized crime gangs such as the Italian-American Mafia usually occupy the middle or upper class stratum of society.
Gangs usually take over a territory in a city or suburb. They call this territory their "turf." One common criminal activity on their turf is "providing protection." This is a common style of extortion in which a gang provides protection from its own members for money.
What class stratum do organized crime gangs occupy?
A. working class
B. lower class and middle class
C. lower class
D. middle or upper class
- Câu hỏi 113857:
Read the text and decide that the statement is TRUE (T), FALSE (F) or NOT GIVEN (NG).
You are aware that the enzyme hunters have been replaced by a new breed of hunters who are tracking genes-the blueprints for each of the enzymes-and are discovering the defective genes that cause inherited diseases-diabetes, cystic fibrosis. These gene hunters, or genetic engineers, use recombinant DNA technology to identify and clone genes and introduce them into bacterial cells and plants to create factories for the massive production of hormones and vaccines for medicine and for better crops for agriculture. Biotechnology has become a multibillion-dollar industry.
Everyone uses recombinant DNA technology to identify and clone genes.
- Câu hỏi 113874:
Read the text and decide that the statement is TRUE (T), FALSE (F) or NOT GIVEN (NG).
When was the last time you saw a frog? Chances are, if you live in a city, you have not seen one for some time. Even in wet areas once teeming with frogs and toads, it is becoming less and less easy to find those slimy, hopping and sometimes poisonous members of the animal kingdom. All over the world, even in remote jungles on the far side of the globe, frogs are losing the ecological battle for survival, and biologists are at a loss to explain their demise. Are amphibians simply over-sensitive to changes in the ecosystem? Could their rapid decline in numbers be signalling some coming environmental disaster for us all?
This frightening scenario is in part the consequence of a dramatic increase over the last quarter century in the development of once natural areas of wet marshland; home not only to frogs but to all manner of wildlife. Yet, there are no obvious reasons why certain frog species are disappearing from rainforests in the Southern Hemisphere which are barely touched by human hand. The mystery is unsett1ing to say the least, for it is known that amphibian species are extremely sensitive to environmental variations in temperature and moisture levels. The danger is that planet Earth might not only lose a vital link in the ecological food chain (frogs keep populations of otherwise pestilent insects at manageable levels), but we might be increasing our output of air pollutants to levels that may have already become irreversible. Frogs could be inadvertently warning us of a catastrophe.
Frogs are important in the ecosystem because they control pests.
- Câu hỏi 113880:
Read the text and decide that the statement is TRUE (T), FALSE (F) or NOT GIVEN (NG).
This frightening scenario is in part the consequence of a dramatic increase over the last quarter century in the development of once natural areas of wet marshland; home not only to frogs but to all manner of wildlife. Yet, there are no obvious reasons why certain frog species are disappearing from rainforests in the Southern Hemisphere which are barely touched by human hand. The mystery is unsett1ing to say the least, for it is known that amphibian species are extremely sensitive to environmental variations in temperature and moisture levels. The danger is that planet Earth might not only lose a vital link in the ecological food chain (frogs keep populations of otherwise pestilent insects at manageable levels), but we might be increasing our output of air pollutants to levels that may have already become irreversible. Frogs could be inadvertently warning us of a catastrophe.
There are many reasons why certain frog species are disappearing from rainforests in the Southern Hemisphere.
