Sex Ratios at Birth

• 出生性别比

Sex Ratios at Birth的用法和样例：

例句

1. Remarkably high sex ratios at birth have been observed recently in Asian populations.
   高出生性别比常常发生在亚洲的人口中。
2. What happens to the sex ratio at birth if fertility is maintained at a low level depends on the evolution of son preference.
   如果生育率维持在低水平上，出生性别比的前景取决于男孩偏好的演化。