A、26%. B、31%. C、35%. D、40%. B根据句(7)可知，如果女性每周运动5个小时，那么得乳腺癌的概率会降低31％。因此答案为[B]。

M: (6-1) Let me switch gears now and turn into the subject of the connection between rigorous exercise and preventing breast cancer. And, specifically I am talking about estrogen negative breast cancers. A study showed that there was a drop between 26 and 40 percent even if you take the lower end of that spectrum. That is significant.
W: It’s a very large decrease. So, one of the first studies with the Nurse’s Health Study followed 3,000 people for 14 years and they saw a between 26 to 40 percent decrease in death and recurrence in individuals who already had breast cancer. This newest study, the California Teacher Study, followed 110,000 women from the earlier mid-90s up until 2002 and they saw that (6-2/7) the women that were exercising the most had the greatest reduction in breast cancer, as you said, about 31 percent, about 5 hours a week.
M: What about the impact of exercise on estrogen positive cancers?
W: Well, the studies before and the school’s latest study have not really differentiated between the two. (8) We’ve always thought that it was through estrogen, because when you exercise, you have lower levels of estrogen, so we thought that was a reason that you got the decrease. (9) This California Teacher Study was in the estrogen negative, um, type of cancer. So it seems, at the moment, that’s just one study, so, at the moment, it’s really looking like it’s all types of breast cancer.
M: So to wrap things up for a woman who gets a diagnosis of breast cancer is difficult. Does it make sound the first thing you would tell that woman to do is go out and start exercising?
W: (10) Well, see your doctor and get a very good medical team and then make sure that exercise is an adjunct to that, and the research that we are doing at the Friedman School is showing that we can get a lot of people exercising. So, um, it’s really important for your brain as well as reducing your risk of breast cancer. And as a woman with a history of Alzheimer in my family, I am certainly gonna keep exercising.
M: A lot of people are gonna pay attention to it. Miriam Nelson, professor, thanks, good to have you here.
W: Oh, my pleasure.
This is the end of Part Two of the interview. Questions 6 to 10 are based on what you have just heard.
6. What is the connection between exercise and preventing breast cancer?
7. According to the California Teacher Study, what percentage of decrease in breast cancer did the women who exercised 5 hours a week have?
8. According to Miriam Nelson, what have they thought was the reason of breast cancer?
9. What did the California Teacher Study study?
10. What is the first thing a woman should do if she gets a diagnosis of breast cancer?