microscope.
A telescope is the most helpful tool when observing the moon.
The most useful tool would have to be diamond pickaxe.
bow and arrow
An eye.
my vibrator
Perhaps the most useful tool in tracking tornadoes is Doppler radar.
A healthy living human brain.
when is the estimation of product is a useful tool
Control Charts
the too that is most useful in word is the print because it allows you to print out what ever you want....
A useful tool would be a spatula.
Most diamonds are used in industry and not in jewelry. Their hardness makes diamond useful as a cutting tool.