A magnifying glass.
The police will investigate the crime. Holmes can investigate anything.
The detective was sent to investigate the dark room.
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Example sentence - The detectives would investigate the crime using the newest technologies.
You could use examine, investigate, probe, seek information, interrogate, analyze, investigate or question
muckrakers
they use their 5 sences
use a thermetor
it was zinc
Iodine-131
Put the glass between yourself and the object you wish to investigate.
Some other words for investigate include examine, inspect, probe, and review. You could also use explore and inquire. The word investigate is a verb.