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 ______.

According to the passage, Pilgrims are ______.

Which of the following statements is not TRUE about Thanksgiving ______?

Lake Vostok is potentially important to scientists because it________.

In Science, a theory is a reasonable explanation of observed events that are related. A theory often involves an imaginary model that helps scientists picture the way an observed event could be produced. A good example of this is found in the kinetic molecular theory, in which gases are pictured as being made up of many small particles that are in constant motion. After a theory has been publicized, scientists design experiments to test the theory. If observations confirm the scientists’ predictions, the theory is supported. If observations do not confirm the predictions, the scientists must search further. There may be a fault in the experiment, or the theory may have to be revised or rejected. Science involves imagination and creative thinking as well as collecting information and performing experiments. Facts by themselves arc not science. As the mathematician Jules Henri Poincare said: "Science is built with facts just as a house is built with bricks, but a collection of facts cannot be called science any more than a pile of bricks can be called a house." Most scientists start an investigation by finding out what other scientists have learned about a particular problem. After known facts have been gathered, the scientist comes to the part of the investigation that requires considerable imagination. Possible solutions to the problem are formulated. These possible solutions are called hypotheses. In a way, any hypothesis is a leap into the unknown. It extends the scientist's thinking beyond the known facts. The scientist plans experiments, performs calculations, and makes observations to test hypotheses. For without hypotheses, further investigation lacks purpose and direction. When hypotheses are confirmed, they are incorporated into theories. 

Which of the following is the main subject of the passage?

According to the passage, what way was used to eliminate the spread of smallpox?

Which one of the statements doesn’t refer to smallpox?

In the first paragraph, the word “elements” is closest in meaning to____.