Most clocks and watches today keep time by applying electric energy to a quartz crystal , a system developed in the 1930s.
(a system; developed; T:in the 1930s) (Most clocks and watches; keep; time; T:today) Context(Most clocks and watches keep,List([0, 34))):(Most clocks and watches; keep time by applying; electric energy; to a quartz crystal)
Most clocks and watches keep,List([0, 34))
a system Most clocks and watches Most clocks and watches
developed keep keep time by applying
T:in the 1930s
time T:today
electric energy to a quartz crystal