A、1969. B、1977. C、1997. D、2000 D录音讲到2000年六月the department of health and human services将一种新工具公诸于世，由后文可以推断这种新工具指的就是BMI。

It is estimated that almost 55 percent of American adults and approximately 10 percent of kids are overweight. But how does one tell the difference between baby fat and weight that causes health risk.
    In June, 2000, the department of health and human services unveiled a new tool that would help answer that question. It revised the familiar children’s growth chart used since 1977 to track height and weight and introduce body mass in this chart for children between the age of two and twenty. The Body Mass Index or BMI is a number derived from a person’s height and weight measurement. It has long been used to determine if adults are overweight.
    The new BMI chart is considered the best tool for assessing whether children are the right size and can identify a child’s likelihood of unhealthy weight gain as early as age two. Armed with a child’s BMI a parent or a doctor can use the new chart to see where a child measures up compared with his or her peers.
    BMI changes with age for kids. A nine-year girl with a BMI of 23 would be near the 97th percent tier and overweight. A 16-year old with the same measure would be in the 75th percent tier and considered normal, because at the 95th percent tier or above, the child is identified as overweight.
    The new chart comes as nutrition experts and doctors focus more on childhood obesity, a reflection of changing nature of modern day life. In 1969, obesity in children was not even an issue. Parents worried about their child’s weight hear the same advice that many adults don’t heed. Eat low-fat diet, rich in fruits and vegetables and get regular exercise. But at least the new chart will have the parents begin the process of changing behavior at an early age.
Question 26-30 are based on the following passage:
26. When was the BMI chart introduced?
27. What is the use of BMI?
28. What is the advantage of the new BMI chart over the traditional children’s growth chart?
29. When can a child be considered overweight?
30. In what aspect can the new chart help parents?