To generalise wildly, there are two ways to control fertility: to have children quickly and then use contraception to stop having more, or to space out births, leaving longer intervals between each.
广泛地说,有两种方式来控制生育:
一种,每个孩子出生间隔尽量短,然后使用避孕的方法以防止生育更多;
二种,将孩子出生时间拉长,使每个孩子的年龄间隔变长。