Infrasounds (frequencies under 20 kHz)
Useful is the actual production of electricity. Non-useful -- unused heat energy released into the environment.
I think a pulley is useful because it can help you and other people to.
Some useful inventions are the light bulb, wheel, and the telephone.
Light , which is useful Heat , which is NOT useful.
infrasound is more useful than sound for detecting volcanic eruptions because it traves a lot further than sound and is hear km away
infrasounds
Infrasounds (frequencies under 20 kHz)
Because some sounds travel very well through water.
Most useful and more useful.
more useful, the most useful
Computers are so useful to us.Bert is not a very useful person.I find that the phone is a useful invention.Make yourself useful and pass me the spanner.Hopefully these sentences are useful to you.
how are mirrors useful ? how are mirrors useful ?
more useful, most useful
more useful and most useful
is nuclear deal useful for us? why nuclear deal is useful for us? is nuclear deal useful for us? why nuclear deal is useful for us? is nuclear deal useful for us? why nuclear deal is useful for us? is nuclear deal useful for us? why nuclear deal is useful for us?
useful