3 sentences

1. 物理学家正在研究这些微观粒子在真空中的运动。

   wù​lǐ​xué​jiā zhèng​zài yán​jiū zhè​xiē wēi​guān lì​zi zài zhēn​kōng zhōng de yùn​dòng.

   Physicists are studying the movement of these microscopic particles in a vacuum.

   Source: Dong Chinese Dictionary

2. 他心胸狭隘，总是为了一些微不足道的小事斤斤计较。

   tā xīn​xiōng xiá'ài, zǒng​shì wèi​le yī​xiē wēi​bù​zú​dào de xiǎo​shì jīn​jīn​jì​jiào.

   He is narrow-minded and always fusses over trivial matters.

   Source: Dong Chinese Dictionary

3. 这些微小的水滴在叶尖上积聚成了一颗巨大的水珠。

   zhè​xiē wēi​xiǎo de shuǐ​dī zài yè jiān shàng jī​jù chéng le yī kē jù​dà de shuǐ​zhū.

   These tiny droplets gathered into a large drop of water at the tip of the leaf.

   Source: Dong Chinese Dictionary