The word “this” in paragraph 3 refers to ...............

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. 

This passage is mainly about ............

The author implies which of the following is true?

Which of the followings is not mentioned as part of the “new media”?

The word “checked” in the second paragraph is closest in meaning to ______.

The system of higher education had its origin in Europe in the Middle Ages, when the first universities were established. In modern times, the nature of higher education around the world, to some extent, has been determined by the models of influential countries such as France and Germany. Both France and Germany have systems of higher education that are basically administered by state agencies. Entrance requirements for students are also similar in both countries. In France, an examination called the baccalauréat is given at the end of secondary education. Higher education in France is free and open to all students who have passed this baccalauréat. Success in this examination allows students to continue their higher education for another three or four years until they have attained the first university degree called a licence in France. Basic differences, however, distinguish these two countries’ systems. French educational districts, called académies, are under the direction of a rector, an appointee of the national government who is also in charge of universities in each district. The uniformity in curriculum throughout the country leaves each university with little to distinguish itself. Hence, many students prefer to go to Paris, where there are better accommodations and more cultural amenities for them. Another difference is the existence in France of prestigious higher educational institutions known as grandes écoles, which provide advanced professional and technical training. Most of these schools are not affiliated with the universities, although they too recruit their students by giving competitive examinations to candidates. The grandes écoles provide rigorous training in all branches of applied science and technology, and their diplomas have a somewhat higher standing than the ordinary licence. In Germany, the regional universities have autonomy in determining their curriculum under the direction of rectors elected from within. Students in Germany change universities according to their interests and the strengths of each university. In fact, it is a custom for students to attend two, three, or even four different universities in the course of their undergraduate studies, and the majority of professors at a particular university may have taught in four or five others. This high degree of mobility means that schemes of study and examination are marked by a freedom and individuality unknown in France. France and Germany have greatly influenced higher education systems around the world. The French, either through colonial influence or the work of missionaries, introduced many aspects of their system in other countries. The German were the first to stress the importance of universities as research facilities, and they also created a sense of them as emblems of a national mind. 

What does the passage mainly discuss?

On March 15, Dunes View Middle School held a contest for school bands. Student bands tried out for the opportunity to perform at the school picnic, which will be held at the end of June. The winner of the contest was the band called Four Square. “We’re very proud that we won the contest and are excited to perform at the picnic,” says Peter Zandt, who plays the guitar in the band. “And since we hope to perform someday at other local places, like restaurants and parks, this will be a great first step.” The contest was the creation of music teacher Mr. Lopez and drama teacher Ms. Cho. The two thought of the idea while discussing recent years’ school picnics. “The picnic is one of the biggest events of the year, but it has become a bit formulaic ,” said Ms. Cho. “The activities are the same every year. We thought that a performance by a student band would make the school picnic more interesting and fun.” Mr. Lopez, Ms. Cho, and three other teachers judged the contest, which took place in the gym. Eight student bands signed up to audition. The bands varied in their musical forms: there were several rock bands, a folk band, and even a jazz band. “I’m disappointed that my band didn’t win, but I think the judges made the right choice,” says student Marisol Varga, a member of the folk trio called The Bell Girls. “Four Square is really good.” To see if the bands could present a wide range of musical skills, the teachers asked them each to prepare two songs: one song with original words, and another in which students played instrumental music only. The judges finally chose the band Four Square as the winner of the contest. Four Square is a rock band with an unusual twist: it includes a violin player! The members of Four Square write their own songs and practice three times a week after school. Students and teachers agreed that the band competition was a big success. All are looking forward to the school picnic in June. 

Which would be the most appropriate headline for the article?

What is probably true about school picnics in recent years?

The word “bounds” in line 5 is closest in meaning to ......

Where did Moore spend most of her adult life?

The mineral particles found in soil range in size from microscopic clay particles to large boulders. The most abundant particles - sand, silt, and clay - are the focus of examination in studies of soil texture. Texture is the term used to describe the line composite sizes of particles in a soil sample, typically several representative handfuls . To measure soil texture, the sand, silt, and clay particles are sorted out by size and weight. The weights of each size are then expressed as a percentage of the sample weight. In the field, soil texture can be estimated by extracting a handful of sod and squeezing the damp soil into three basic shapes; (1) cast, a lump formed by squeezing a sample in a clenched fist; (2) thread, a pencil shape formed by rolling soil between the palms; and (3) ribbon, a flatfish shape formed by squeezing a small sample between the thumb and index finger. The behavioral characteristics of the soil when molded into each of these shapes, if they can be formed at all, provides the basis for a general textural classification. The behavior of the soil in the hand test is determined by the amount of clay in the sample. Clay particles are highly cohesive, and when dampened , behave as a plastic. Therefore the higher the clay content in a sample, the more refined and durable the shapes into which it can be molded. Another method of determining soil texture involves the use of devices called sediment sieves, screens built with a specified mesh size. When the soil is filtered through a group of sieves, each with a different mesh size, the particles become grouped in corresponding size categories. Each category can be weighed to make a textural determination. Although sieves work well for silt, sand, and larger particles, they are not appropriate for clay particles. Clay is far too small to sieve accurately; therefore, in soils with a high proportion of clay, the fine particles are measured on the basis of their settling velocity when suspended in water. Since clays settle so slowly, they are easily segregated from sand and silt. The water can be drawn off and evaporated, leaving a residue of clay, which can be weighed. 

The author mentions "several representative handfuls" in the passage in order to show ______.