听力原文: Heart failure is a condition in which the heart cannot pump as much blood as the
In the United States, doctors say about five million people have this major cause of sickness and death. They say heart failure is the leading cause of hospital treatment for people aged sixty-five and older. But these doctors say the problem of heart failure has yet to be fully investigated.
Researchers at the Mayo Clinic in Minnesota did a study of the last twenty years. They expected to find that heart failure has become more common. Hospital admissions for heart failure have increased. But they found that the percentage of the population developing heart failure has not changed. Instead, survival rates have improved.
Which one of the following is a sign of heart failure?
A.Breathing difficulties.
B.High blood pressure.
C.Headache.
D.High body temprature.