rén / kǒu / jīn / zì / tǎ / kě / yǐ / xiǎn / shì / yí / ge / guó / jiā / bù / tóng / nián / líng / duàn / de / rén / kǒu / bǐ / lì人口金字塔可以显示一个国家不同年龄段的人口比例。A population pyramid can show the proportions of different age groups in a country.