Blood is made up of two main elements: (1) plasma, which is largely water and proteins, and (2) the solid components of blood—red blood cells, white cells, and platelets (important for forming clots). If a patient has lost a lot of blood, he or she may receive a transfusion of “whole blood,” which includes red blood cells and plasma. However, sometimes the patient needs only an increase in the volume of liquid in the bloodstream, in which case plasma alone may be substituted. A person must be tested for blood type before receiving certain kinds of transfusions because of differences in the ways that red blood cells react to one another. Under what conditions would such testing be necessary?

Questions 3 through 5 are based on the following information. Coal is formed from the material of plants and other organisms that lived on land and whose remains were covered by mud, which later became rock. Coal is classified by carbon content. Peat = The remains of plants and organisms that, because they were covered in bogs, were prevented by a lack of oxygen from completely decaying. Still a porous, soft brown mass, peat has a carbon content of 52%–60%. Lignite = In time, peat turns into lignite, a soft coal-like substance that is 60%–65% carbon. Subbituminous coal = With more time, heat, and pressure, lignite changes into subbituminous coal, which is about 65%–75% carbon. Bituminous coal = After even more heat and pressure, subbituminous coal turns into bituminous coal with a carbon level of 75%–85%. Anthracite = This is bituminous coal subjected to another million years of heat and pressure. Anthracite has a carbon level of 85%–95% and will burn only at extremely high temperatures. A researcher analyzes a piece of coal and finds that it is unusually dense and burns only when subjected to very intense heat. What is the lowest percentage of carbon that this coal is likely to contain? Enter the _____ %.

Questions 3 through 5 are based on the following information. Coal is formed from the material of plants and other organisms that lived on land and whose remains were covered by mud, which later became rock. Coal is classified by carbon content. Peat = The remains of plants and organisms that, because they were covered in bogs, were prevented by a lack of oxygen from completely decaying. Still a porous, soft brown mass, peat has a carbon content of 52%–60%. Lignite = In time, peat turns into lignite, a soft coal-like substance that is 60%–65% carbon. Subbituminous coal = With more time, heat, and pressure, lignite changes into subbituminous coal, which is about 65%–75% carbon. Bituminous coal = After even more heat and pressure, subbituminous coal turns into bituminous coal with a carbon level of 75%–85%. Anthracite = This is bituminous coal subjected to another million years of heat and pressure. Anthracite has a carbon level of 85%–95% and will burn only at extremely high temperatures. Steel is made in a process in which iron is combined with carbon at extremely high temperatures. Which of the following types of coal might be most useful in this process?

Questions 3 through 5 are based on the following information. Coal is formed from the material of plants and other organisms that lived on land and whose remains were covered by mud, which later became rock. Coal is classified by carbon content. Peat = The remains of plants and organisms that, because they were covered in bogs, were prevented by a lack of oxygen from completely decaying. Still a porous, soft brown mass, peat has a carbon content of 52%–60%. Lignite = In time, peat turns into lignite, a soft coal-like substance that is 60%–65% carbon. Subbituminous coal = With more time, heat, and pressure, lignite changes into subbituminous coal, which is about 65%–75% carbon. Bituminous coal = After even more heat and pressure, subbituminous coal turns into bituminous coal with a carbon level of 75%–85%. Anthracite = This is bituminous coal subjected to another million years of heat and pressure. Anthracite has a carbon level of 85%–95% and will burn only at extremely high temperatures. Steel is made in a process in which iron is combined with carbon at extremely high temperatures. Which of the following types of coal might be most useful in this process? Drag and drop the appropriate type of coal into each box. (For this practice test, select the appropriate letter in the following option) The type of coal most likely found closest to the surface of the earth: The type of coal that contains the greatest amount of carbon per kilogram: