But the researchers were able to isolate the link between drinking and breast cancer by controlling for a host of other risk factors, such as family history of the disease and age at first pregnancy.
但是研究者可能会通过控制其他的患病因素会割裂饮酒与患乳腺癌的联系，比如家族病史和初次怀孕年龄。
2
The cause is not definitely known but family history, pregnancy or having an occupation that involves a lot of standing are possible risk factors.
病因还不太清楚，家族史、怀孕或是常期站立的工作经常是引起痔的危险因素。
3
Prenatal history. Medical problems during this pregnancy should be reviewed, including urinary tract infections, diabetes, or hypertension.