Definition: Given a scientific passage and an answer, generate a question for the given answer.
Input: Passage: Mercury manometers are often used to measure arterial blood pressure. An inflatable cuff is placed on the upper arm as shown in Figure 11.17. By squeezing the bulb, the person making the measurement exerts pressure, which is transmitted undiminished. Answer: blood pressure
Output:
What are mercury manometers often used to measure?