
A simple “opener” for metal cans with lacquer or varnish can be done in just a minute from block of wood and two nails.
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School hydrometeorological station
"The school automatic weather station, constructed by students of secondary school No. 5 in the city of Klin, is of technical interest. The precipitation sensor and its registration on the...
LIGHTING CONTROLLED BY AUTOMATIC SWITCH
When lighting fixtures and electricity were cheap, the question of a thrifty approach to choosing lighting for stairwells was not seriously considered by anyone.
But life has taught...