These are the most frequently used words in this book.
air
amount
another
atoms
battery
between
body
brake
cable
called
car
cell
change
clock
computer
contains
control
create
data
day
device
different
digital
disk
does
down
electrons
end
energy
engine
example
file
first
force
frequency
fuel
gear
get
hard
heat
hsw
information
inside
internet
keep
know
let
light
line
links
liquid
long
look
move
need
number
oil
page
parts
people
per
phone
power
pressure
process
produce
provide
radio
satellite
screen
second
see
server
set
several
signal
simple
small
sound
space
speed
switch
system
take
tape
things
three
time
transmission
turns
tv
two
types
use
used
water
wave
web
wire
work