twin
Twins, nonsense twins, twins, twins, refers to the birth of a fetus in the birth of two individuals at the same time the situation. Human fertility in the usual circumstances, women every menstrual cycle, the ovary will only release an egg, fertilization will only develop into an embryo, born naturally a child born. But in rare cases there may be two or even more embryos developed, called twin, twin or twin. There are three kinds of sex with twins: men's doubles, women's doubles and mixed doubles; one of the mixed men and women, Oriental tradition called "twins". In addition to twins, triplets, quadruplets and even more births may also naturally produce, of course, the more rare fetal rare. ...