The gender is determined by the father 's sperms not by the mother .
性别是由爸爸的精子决定的而不是妈妈。
As soon as a man gets an erection he starts producing fluid which includes sperms which is enough for a woman to get pregnant .
男人一旦勃起就开始产生液体，这些液体中包括足够让女人怀孕的精液。
When all the other sperm were just swimming around , bob was doing sprints and lifting weights all the other sperms asked him one day , " why don 't you just swim around like us ? "
Remember , sperms can survive for several days after sex , so even if you have sex during periods , it may still stay in your body long enough to get you pregnant .
