蚊

In a sentence

• 昨晚有很多蚊子在房间里飞来飞去。

  Last night, there were many mosquitoes flying around in the room.

  Here, 蚊 is used as a noun referring to the insect commonly known as a mosquito.

• 为了防止蚊虫叮咬，我们点了蚊香。

  To prevent mosquito bites, we lit mosquito repellents.

  In this instance, 蚊 is a component in the compound noun 蚊香 referring to mosquito repellents.

• 夏季夜晚常见的飞虫之一是蚊子。

  One of the commonly seen flying insects on summer nights is the mosquito.

  Here, 蚊 is the root word in 蚊子, explicitly naming the mosquito insect.