shí / yàn / rén / yuán / bǎ / niào / sù / jiā / rù / shuǐ / zhōng / guān / chá / tā / de / róng / jiě / qíng / kuàng实验人员把尿素加入水中,观察它的溶解情况。The laboratory staff added urea to the water and observed how it dissolved.