医学 >>> 性科学 >>> 性生物学 性生理学 性心理学 性医学 性社会学 性伦理学 性教育
搜索结果: 1-3 共查到性科学 Risks相关记录3条 . 查询时间(0.099 秒)
Context: Since the 1980s, the age at which U.S. teenagers, especially minority youth, begin having sex has decreased. There is limited information on the relationship between early sexual initiation a...
Context: Past research has revealed that having a sister who gave birth as a teenager is associated with increases in young people's likelihood of engaging in risky sexual behavior. To date, however, ...
The powerful demographic trend toward aging of populations in most countries has appropriately focused attention on the health problems of older men. Although there is agreement that serum total, bi...

中国研究生教育排行榜-

正在加载...

中国学术期刊排行榜-

正在加载...

世界大学科研机构排行榜-

正在加载...

中国大学排行榜-

正在加载...

人 物-

正在加载...

课 件-

正在加载...

视听资料-

正在加载...

研招资料 -

正在加载...

知识要闻-

正在加载...

国际动态-

正在加载...

会议中心-

正在加载...

学术指南-

正在加载...

学术站点-

正在加载...