HP
加入词篮spectrum
spectroscopy
spectroscope
spectrometer
convex mirror
concave mirror
real image
virtual image
spectrometer
focus
focusing
focal
focal point
focal length
oscillate
oscillation
oscillator
vibrate
vibration
quake
resonance
resonate
interference
interfere
acoustics
echo
reverberation
reverberate
wave
wavelength
amplitude
frequency
period
sound wave
shock wave
airwaves
microwave
short wave
short-wave
ultrasound
sonic
supersonic
ultrasonics
sonar
radar
electric charge
negative terminal
positive terminal
electric field
potential
repel
repulsion
electric current
alternating current
direct current
ampere
voltage
capacitance
resistivity
resistance
fuse
transformer
volt
kilowatt
watt
conductor
conduct
conduction
conductive
conductivity
semiconductor
pressure
stress
friction
strain
mass
inertia
inertial
weightless
weightlessness
keep
kept
stay
retain
keep up
ecology
ecologist
ecological
ecologically
eco-friendly
ecosystem
biodiversity
biosphere
variety
a variety of
diversity
species
endanger
