“epidemiological study”可以造什么句，epidemiological study造句

Comment: in a previous epidemiological study, the prevalence of dysmenorrhea was inversely associated with dietary intake of both fish oil and vitamin B12.

These three main categories of epidemiological study may each require, as a preliminary phase, a fourth and rather different approach-that is, a method study.

Whether or not the cleaning products are a direct cause of asthma, or simply a trigger for people who already have the disease, isn't clear from this epidemiological study.