shut – v. to close

accurate – adj. free from mistakes or errors

transmit – v. to send in the form of electrical signals to a radio, television or computer

permeates – v. to pass or spread through something

frequency – n. the number of times a sound or radio wave is repeated in a period of time

appliance – n. a machine that is powered by electricity and that is used in people's houses to perform a certain job

irrigation – n. describing a system to supply water using man-made means (for agriculture)

standard – n. a fixed official unit of measurement

propagation – n. the act of causing to spread out

tune – v. to change and improve the sound of a musical instrument