yán / jiū / rén / yuán / lì / yòng / àn / xiàn / guāng / pǔ / lái / pàn / duàn / qì / tǐ / zhōng / hán / yǒu / nǎ / xiē / yuán / sù

研究人员利用暗线光谱来判断气体中含有哪些元素。

Researchers use dark-line spectra to determine which elements are present in a gas.