astronomy
bacterium
biology
color
colorful
communication
connection
contour
design
device
disease
electric
electrical
electricity
energy
equipment
germs
icon
illness
illustration
infection
instrument
isolated
lens
line
linear
measure
measurement
medical
medicine
meter
microbe
microbiology
organism
outline
power
science
set
sign
space
spyglass
symbol
technology
tool
virus
voltage