医药科学
肛交
Any type of sexual activity that leads to orgasm including masturbation, anal sex, oral sex and intercourse can trigger sex headaches.
CNN: Sex headaches
"There's been some speculation about whether teenagers were substituting oral or anal sex for vaginal sex and I found that wasn't so, " says Rosenbaum.
CNN: Virginity pledges don't mean much, study says
In a recent survey in Cambodia, 40% of men who had had anal sex with other men in the previous month had also had sex with women in that time.
ECONOMIST: The struggle against AIDS in Asia is far from over
英汉双解词典包含3185865条英汉词条，基本涵盖了全部常用单词的翻译及用法，是英语学习的有利工具。