shí / yàn / shì / lǐ / shǐ / yòng / zhèng / dīng / mí / shí / bì / xū / yuǎn / lí / huǒ / yuán

实验室里使用正丁醚时，必须远离火源。

When using butyl ether in the laboratory, you must stay away from sources of ignition.