听完学生的提问后,教授沉思良久才给出谨慎的回答。Tīng wán xuéshēng de tíwèn hòu, jiàoshòu chénsī liángjiǔ cái gěi chū jǐnshèn de huídá.After hearing the student's question, the professor pondered for a long while before giving a cautious answer.
他坐在湖边沉思,一动不动地看着水面。Tā zuò zài húbiān chénsī, yí dòng bú dòng de kàn zhe shuǐmiàn.He sat by the lake lost in thought, staring motionless at the water.
听了朋友的建议,她低头沉思了一会儿。Tīng le péngyou de jiànyì, tā dī tóu chénsī le yíhuìr.After hearing her friend's advice, she lowered her head and thought for a while.