Questions 17 to 20 are based on the following passage. At the end of the passage, you will be given 20 seconds to answer the questions. Now, listen to the passage. Which of the following is INCORRECT according to the passage
A．The number of school injuries has doubled in ten years. B．About 20% of American children and teenagers are overweight. C．Only 2% of the injuries treated in hospitals are serious. D．Injuries increased 1.5 times as many as that during the past decade.