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Blood is indeed in the news, for on the heels of that announcement comes a report of tests carried out in the United States and Japan on artificial blood. After an accident, time is crucial for a person suffering from extensive blood loss, and a transfusion of real blood 5 must often be preceded by a time-consuming test for blood type. Plasma does not require such a test but, because it can carry little oxygen it is not a wholly satisfactory substitute. Perfluorocarbons appear to offer an answer. They are utilized in combination with and emulsion called Fluosol-DA, which provides a number of additional advantages 10 over real blood. These include the absence of need for blood tests, the fact that it can be frozen for as long as two years, its elimination eventually as a gas through the lungs, and the impossibility of its transmitting such problems as hepatitis.
1. What was the preceding paragraph probably about ?
2. Why, according to the passage, is a transfusion of real blood sometimes problematical ?
3. What can be inferred from the passage about perfluorocarbons ?
4. Which of the following is mentioned as being as advantage of Fluosol-DA over real blood ?
5. What would be the most suitable title for this extract ?