3 sentences

1. 这个问题涉及国家安全。

   zhè gè wèn​tí shè jí guó​jiā ān​quán.

   This issue involves national security.

   Source: Dong Chinese Dictionary

2. 他涉世未深，还不懂社会的复杂。

   tā shè shì wèi shēn, hái bù dǒng shè​huì de fù​zá.

   He is inexperienced and doesn't yet understand the complexity of society.

   Source: Dong Chinese Dictionary

3. 他跋山涉水，历经艰辛才找到那株草药。

   tā bá shān shè shuǐ, lì​jīng jiān​xīn cái zhǎo​dào nà zhū cǎo​yào.

   He trekked across mountains and rivers, enduring hardships to find that herb.

   Source: Dong Chinese Dictionary