4 sentences

1. 他不愿虚度大好年华。

   tā bù yuàn xū​dù dà​hǎo nián​huá.

   He does not want to waste the best years of his life.

   Source: Dong Chinese Dictionary

2. 虚度光阴是人生最大的悲哀。

   xū​dù guāng​yīn shì rén​shēng zuì dà de bēi'āi.

   Wasting time is the greatest sorrow of life.

   Source: Dong Chinese Dictionary

3. 不要虚度光阴。

   bù yào xū​dù guāng​yīn.

   Don't idle your time away.

   Source: Dong Chinese Dictionary

4. 老师常用这个案例来警示学生不要虚度光阴。

   lǎo​shī cháng yòng zhè gè àn​lì lái jǐng​shì xué​sheng bù yào xū​dù guāng​yīn.

   The teacher often uses this example to warn students not to waste their time.

   Source: Dong Chinese Dictionary