family size的用法和樣例：
例句
- The major reason for the reduction of family size is a reduction in the number of births.
家庭規模縮小的主要原因是生育子女數量的減少。 - The family size has become gradually smaller and nucleus family is becoming the major form of modern Chinese families.
家庭規模逐漸縮小，核心家庭正在成為當代中國家庭的主要形式。
