1 sentence

1. 地震学家通过分析地震波的走时来研究地球内部结构。

   dì​zhèn​xué​jiā tōng​guò fēn​xī dì​zhèn​bō de zǒu​shí lái yán​jiū dì​qiú nèi​bù jié​gòu.

   Seismologists study the Earth's internal structure by analyzing the travel time of seismic waves.

   Source: Dong Chinese Dictionary