4 sentences

1. 世上书太多，而时间太少。

   shì​shàng shū tài​duō, ér shí​jiān tài​shǎo.

   There are too many books in the world and too little time.

   Source: CCMatrix

2. 不要合上书，只要翻过那一页。

   bù​yào hé shang shū, zhǐ​yào fān guò nà yī yè.

   Don't close the book, just turn the page.

   Source: CCMatrix

3. 教师通常用粉笔在黑板上书写。

   jiào​shī tōng​cháng yòng fěn​bǐ zài hēi​bǎn shang shū​xiě.

   Teachers usually write on the blackboard with chalk.

   Source: AI Challenger 2017

4. 如果你不能或不愿意，是时候让你合上书，做点别的事情了。

   rú​guǒ nǐ bù​néng huò bù​yuàn​yi, shì shí​hou ràng nǐ hé shang shū, zuò diǎn bié​de shì​qing le.

   If you can't or won't, it's time for you to close the book and do something else.

   Source: CCMatrix