23．Paragraph 2______.
24．Paragraph 3______.
25．Paragraph 4______.
26．Paragraph 7______.
A．Risk of Screening to Younger Women
B．Investigating the Effect of Screening
C．Effects Predicted by Two Different Models
D．Treatment of Cancers
E．Minimizing of Radiation Exposure
F．Factors That Trigger Cancers
27．If discovered early．breast cancer may_____．
28．Medical benefits of screening the younger women are_____．
29．Advantages of screening women under 50 are_____．
30．Radiation exposure should be_____．
A．be costly
B．harmful
C．be cured
D．still open to debate
E．reduce the risk of radiation triggering a cancer
F．reduced to the minimum