Suggest that they study

The results of this study suggest that jobs with long working hours are not more risky merely because they are concentrated in inherently hazardous industries or occupations.

这项研究的结果显示，长时间的工作之所以风险更大并不仅仅因为这类工作所在的行业或职业本身有危险。

They also suggest that there is a link between the sociality of mammals and the size of their brains relative to body size, according to a study published in the PNAS journal.

同时，他们还发现哺乳动物的社会性同其大脑相较于体型的尺寸有着某种千丝万缕的联系。这一研究成果已经在美国国家科学院院报(PNAS journal)上发表。

They are also likely to give up a range of health habits that help protect against disease and early death, results of a study suggest.

一项研究结果显示，他们还可能会舍弃一系列有益健康的习惯，这些习惯有助于预防疾病及早逝。