What are the advantages of using context clues as your primary tool/strategy for discovering the definitions of unknown words? what are the disadvantages?

An advantages of using context clues to figure out the definition of a word is that it saves you time during a timed exam and helps you quickly move on. A disadvantage is that many times words have multiple meanings and although the clues lead to one definition another might best fit it.

Afirefighter is a rescuer extensively trained in firefighting, primarily to extinguish hazardous fires that threaten life, property and the environment as well as to rescue people and animals from dangerous situations.  just cut some parts to make them shorter and add some of your facts or what describes them most. or what they are supposed to do.