There are two groups of women when it comes to screening mammography -- women in whom mammography works very well and has saved thousands of lives and women in whom it doesn't work well at all.
在乳腺X光造影诊断中， 有两类女性： X光造影诊断对其中一类十分有效， 已经拯救了数千人的生命； 但对另一类却无法做出有效诊断。