yán / jiū / rén / yuán / àn / nián / líng / zǔ / bǐ / jiào / le / liǎng / zǔ / rén / de / jiàn / kāng / zhuàng / kuàng

研究人员按年龄组比较了两组人的健康状况。

The researchers compared the health conditions of two groups by age.