Shí / yàn / shí / lǎo / shī / tí / xǐng / wǒ / men / bú / yào / zhí / jiē / jiē / chù / liú / suān / tóng

实验时，老师提醒我们不要直接接触硫酸铜。

During the experiment, the teacher reminded us not to touch copper sulfate directly.