How to test fluorescent bulbs<br>Look for dark areas at the base of the bulb. When bulbs age and have been used for a long time, brown spots will appear. If darkness begins to form at the ends of the tube, the bulb may be near its end.
Brown spots show that the bulbs have little age and will be able to be used for a long time. 
( z1 show :ARG0 ( z2 spot :mod ( z3 person :name ( z4 name :op "Brown" ) ) ) :ARG1 ( z5 and :op ( z6 age :ARG1 ( z7 bulb ) :ARG2 ( z8 little ) ) :op ( z9 possible :ARG1 ( z10 use :ARG1 z7 :ARG1-of ( z11 long ) ) ) ) )