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.

It can be inferred that the names of the three basic shapes mentioned in paragraph 2 reflect ______.

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• The phrase ‘suck out’ in paragraph 2 is closest in meaning to which of the following?

• Which of the following statements is NOT true?

• Nowadays, there are ............

ZUNIA12

• The word “astonished” in paragraph 4 can be best replaced by__________.

• The passage is mainly about the subject of .............

• Which of the sentences below expresses the essential information in the italic sentence in paragraph 3? Incorrect choices change the meaning in important ways or leave out essential information.

• According to paragraph 1, which of the following is NOT true?

•  In what way is Juliette’s current job better her first job?

• The word “eliminate” in paragraph 5 could be best replaced by which of the following words?

• Why does the author mention spaghetti?

• What is the author's main purpose?

• According to the passage, what did people have to do first to settle an area?

• The word “accelerated” in paragraph 5 is closest in meaning to ______.

• Which of the following is the best title for the passage?

• According to the text, teaching requires a combination of many things EXCEPT ________.

• The word "innovative" in line 1 could best be replaced by ...............

• What does the phrase “you have got it out of your system” in passage mean?

• According to the passage, what causes the unique color and look of hummingbirds?

• The word "thrive" is closest in meaning to ........

• The word "scrutinized" in the fourth paragraph could be replaced by .............