birth proportion of sexuality的用法和樣例：
例句
- Remarkably high sex ratios at birth have been observed recently in Asian populations.
高出生性別比常常發生在亞洲的人口中。 - What happens to the sex ratio at birth if fertility is maintained at a low level depends on the evolution of son preference.
如果生育率維持在低水平上，出生性別比的前景取決於男孩偏好的演化。
