our naked eyes...
Telescope.
Radar
Microscope is the most common instrument used by biologist.
Usually during the night.
Telescope
A keyboard instrument is any musical instrument played using a musical keyboard. Examples are pianos, organs, and electronic Musical Instruments.In common language, it is mostly used to refer to keyboard-style synthesizers.
The janggu and buk are the common drum instruments found in the song. The gayageum is the common string instrument used. The piri is the common woodwind used. See the related link for further descriptions of each instrument.
The common instrument used to measure time is a clock. Clocks come in various forms such as analog clocks, digital clocks, and atomic clocks, all of which are designed to accurately measure and display time.
the adenoid curette, an instrument that has a sharp edge in a perpendicular position to its long handle. Various sizes of curettes are available
The common terms are endoscopy or sigmoidoscopy or endoscope.
The instrument to measure wind resistance is called an anemometer or wind-meter. It is a common instrument used in weather stations.
The doctor had to flip back their upper eyelids with a hooked instrument to examine the eyeball for disease--Trachoma. A common instrument was the buttonhook.