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DG

Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer to each of the questions from 43 to 50.

          Carbon dating can be used to estimate the age of any organic natural material; it has been used successfully in archeology to determine the age of ancient artifacts or fossils as well as in a variety of other fields. The principle underlying the use of carbon dating is that carbon is a part of all living things on Earth. Since a radioactive substance such as carbon-14 has a known half-life, the amount of carbon-14 remaining in an object can be used to date that object.

          Carbon-14 has a half-life of 5,570 years, which means that after that number of years, half of the carbon- 14 atoms have decayed into nitrogen-14. It is the ratio of carbon-14 in that substance that indicates the age of the substance. If, for example, in a particular sample the amount of carbon-14 is roughly equivalent to the amount of nitrogen-14, this indicates that around half of the carbon-14 has decayed into nitrogen-14, and the sample is approximately 5,570 years old. 

          Carbon dating cannot be used effectively in dating objects that are older than 80,000 years. When objects are that old, much of the carbon-14 has already decayed into nitrogen-14, and the molecule amount that is left doesn’t provide a reliable measurement of age. In the case of older objects, other age-dating methods are available, methods which use radioactive atoms with longer half-lives than carbon has.

It is implied in the passage that______.

A. carbon dating has no known uses outside of archeology

B. fossils cannot be age-dated using carbon-14

C. carbon dating could not be used on an item containing nitrogen

D. carbon-14 does not have the longest known half-life

DG

Read the following passage and mark the letter A, B, C or D on your answer sheet to indicate the correct word for each of the questions.

            It is commonly believed in the United States that school is where people go to get an education. Nevertheless, it has been said that today children interrupt their education to go to school .The distinction between schooling and education implied by this remark is important.                  

Education is much more open-ended and all-inclusive than schooling. Education knows no bounds. It can take place anywhere, whether in the shower or on the job, whether in a kitchen or on a tractor. It includes both the formal learning that takes place in schools and the whole universe of informal learning. The agents of education can range from a revered grandparent to the people debating politics on the radio, from a child to a distinguished scientist. Whereas schooling has a certain predictability, education quite often produces surprises. A chance conversation with a stranger may lead a person to discover how little is known of other religions. People are engaged in education from infancy on. Education, then, is a very broad, inclusive term. It is a lifelong process, a process that starts long before the start of school, and one that should be an integral part of one's entire life.            

Schooling, on the other hand, is a specific, formalized process, whose general pattern varies little from one setting to the next. Throughout a country, children arrive at school at approximately the same time, take assigned seats, are taught by an adult, use similar textbooks, do homework, take exams, and so on. The slices of reality that are to be learned, whether they are the alphabet or an understanding of the workings of government, have usually been limited by the boundaries of the subject being taught. For example, high school students know that they are not likely to find out in their classes the truth about political problems in their communities or what the newest filmmakers are experimenting with. There are definite conditions surrounding the formalized process of schooling

The passage supports which of the following conclusions?

A. Without formal education, people would remain ignorant 

B. Education systems need to be radically reformed 

C. Going to school is only part of how people become educated 

D. Education involves many years of professional training