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 .

演员们说他们明白不用安全套的危害，但认为现在的一些行业活动，如每月放映性病宣传片等足已保护他们。