All sexually active women can be vulnerable to hiv infection .
所有性活动频繁的女性都易感染艾滋病。
Reproducing sexually may disrupt beneficial genetic combinations and lower the mean fitness of offspring .
有性生殖则可能破坏这种有利的基因组合,降低后代的平均适应能力。
When men are sexually interested , they start playing with circular objects .
当男子对性感兴趣的时候,他们会开始把玩环形的东西。
Aids is a sexually transmitted disease with no scientific evidence for arthropod transmission .
艾滋病是性传播疾病,并且不存在媒介节肢动物传播的科学理论依据。
Performers said they understood the risks of not using condoms but believed current industry practices which involve screening for some sexually transmitted diseases monthly were enough to protect them .