墨尔本PTE 阅读排序 2958

A. One in eight women in the U.S. are diagnosed with breast cancer during their lifetimes, but its origins remain unknown in most cases.   

B. According to a growing body of research, bacteria may be one of those environmental factors.   

C. More recent work suggests that this may be because breast milk supports the growth of beneficial microorganisms.   

D. Age, genetic predisposition and environmental changes are often implicated.   

E. For instance, as early as the 1960s a number of studies have found that breast-feeding is associated with a lower risk of breast cancer.