智力年龄

tā jīn nián suì dàn zhì lì nián líng wéi suì

她今年15岁，但智力年龄为4岁。

She is 15 but has a mental age of 4.

zhì lì nián líng wéi jiǔ suì de èr shí wǔ suì nán zǐ

智力年龄为九岁的二十五岁男子

25-year-old man with a mental age of nine