以下为句子列表：
英文: However, most often the case is less dramatic: Some people who engage in coitus simply do not know about contraception, or they are unable to get contraceptives, or they are young, careless and irresponsible, or the contraceptives they use do not work.
中文: 可是，最常见的则是荒唐可笑：那些盲目投入性行为的人对避孕一无所知，或不能得到避孕药具，或他们少不省事、粗心大意和缺乏责任心，或他们所使用的避孕药具不起作用。
更详细...
英文: Proestrus: The female attracts males, has a bloody vaginal discharge and her vulva is swollen. Proestrus lasts approximately nine days; the female, however, will not allow coitus at this time.
中文: 发情前期：母犬开始引诱公犬，阴道有血渗出，阴户涨大。发情前期约持续九天，不过，这段时间，母犬并不与公犬交配。
更详细...
|
