In the study, the authors examined 20 preterm infants with a mean gestational age at birth of 29 weeks (range 26-35) and who were otherwise medically stable.

在这项研究中，作者观察20个平均出生胎龄在29周(从26 - 35周不等)的早产儿，他们都必须是病情稳定。

youdao

Between 1970 and 2000 the mean age at which women had their first child in a range of OECD countries rose by more than a year every decade, and many more women now have their families in their 30s.

1970到2000年间，经合组织各国妇女平均生育第一个孩子的年龄，每隔十年就增长一岁；此外，更多妇女在30多岁时才建立家庭。

youdao

Data were collected from 332 African-Americans and 775 Hispanics with a mean age of 41.7 years at baseline and an age range from 18 to 81 years.

数据收集于332名非洲裔美国人和775名西班牙人，其年龄分布为18 - 81岁，基线水平的平均年龄为41.7岁。

youdao

Between 1970 and 2000 the mean age at which women had their first child in a range of OECD countries rose by more than a year every decade, and many more women now have their families in their 30s.

ECONOMIST: Most of the rich world is short of babies