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Electronic

Explanation:

Electronic thermometers have a digital screen that displays the temperature that you are trying to measure.

Disposable thermometers don't have a digital screen but are like a strip that measures.

Mercury-free thermometers are like the old mercury thermometers and they measure with a substance that moves up the scale with printed temperature markings.

Glass thermometers are just regular thermometers but still not electronic and digital panels require it to be electronic.