它应该看上去很容易浏览,有一个合理的主次关系。
A cusp is also called a stationary point or point of retrogression gression.尖点也叫做平稳点或逆行点。
Butt couples blessed with strength and ag gression rather than looks are better off having boys, as these characteristics are of more use to males.比起长相好的夫妇,那些体力更强、更有进取心的夫妇更容易生儿子,因为这些特质对男性更有用。