But several demographicstudies have shown that even women just considered "overweight," with a body mass index of 25-30, may also be at increased risk of contraceptive failure.
然而一些人口研究的结果显示，那些身体质量指数超过25，不到30的女性也存在不断增加的避孕风险。
2
Not everyone with high CO2 levels had a near-death experience, and previous studies have found that demographic and psychological factors are also involved.
不是所有血液中二氧化碳浓度高的人都会有这种经历，先前的研究发现人口学和心理学上的因素也起到了影响。
3
Many studies abroad proved difficult as the demographic characteristics of the green consumer market segmentation variables.