英文關鍵字
backround
ball
blackboard
board
calculus
chalk
charge
circling
class
classroom
college
current
detail
device
discharge
education
electrical
electricity
electron
electrostatic
energy
equipment
experience
formula
generator
influence
instrumentation
machine
math
measurement
metal
object
old
physical
powerful
rotate
school
science
sign
solution
spark
spin
stainless
static
table
tool
volt
voltage
wimshurst