A blood test is an extremely useful source of information about the health of a body. Because blood is affected by many medical conditions, the shape, size, behaviour, and numbers of blood cells reveal a lot, so blood tests are used to form diagnoses, and to monitor illness and the effectiveness of treatment. A blood test is fast, safe, and fairly reliable. Some tests can be done with only a drop of blood, whereas others may need a lot more. Blood tests give information about such thing as blood chemistry, kidney and liver function, hormone, cholesterol and glucose levels, and numbers of antibodies.
Правильным переводом подчеркнутого грамматического явления является …