Questions 8 and 9 are based on the following news. At the end of the news item, you will be give 10 seconds to answer each of the two questions. Now listen to the news. Wijngaarden will further focus his research on whether ______.

A．there is a definite relationship between high levels of lead and death.
B．the patients with brain tumors have higher levels of lead in their bones.
C．some workers have higher risks of developing brain cancers than others.
D．higher levels of lead have a long-term effect on children over a lifetime.