Assertion: electric toothbrush's movement | /r/HasProperty | emitted by ultrasonic toothbrush
Facets:
Source sentences:
text: Because of the fact that ultrasonic frequencies are beyond the audible range and the amplitude of movement emitted by an ultrasonic toothbrush is typically too small to be perceived, the ultrasound is imperceptible to humans and it may not be apparent that a brush running in pure ultrasound is turned on.