Choose the correct word for each definition.

Choose the correct option.

To study something carefully. [To introduce|To investigate|To invent]
Something strange or unexplainable. [A mystery|A mistake|A mysticism]
Something created for the first time. [An investigation|An invalidation|An invention]
An important discovery. [A breakout|A breakdown|A breakthrough]
Something that wasn't known before. [A discovery|A deployment|A disbalance]