2 sentences

1. 下背部与地板之间应存在小的间隙。

   xià bèi​bù yǔ dì​bǎn zhī​jiān yīng cún​zài xiǎo de jiàn​xì.

   There should be a small gap between your lower back and the floor.

   Source: CCMatrix

2. 现在，我可以在课堂间隙或者是不在电脑旁边的时候使用平板电脑/手机了。

   xiàn​zài, wǒ kě​yǐ zài kè​táng jiàn​xì huò​zhě shì bù​zài diàn​nǎo páng​biān de shí​hou shǐ​yòng píng​bǎn​diàn​nǎo/ shǒu​jī le.

   Now, I can use my tablet/phone between classes or when I am not near my computer.

   Source: CCMatrix