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 appear when the bulbs have so much long time for use.
The sentence is wrong because it states the bulbs will have a long time for use with brown spots. The system found it difficult because it seemed like they would have a long time, not a short time.
( z1 appear :ARG1 ( z2 spot :ARG1-of ( z3 brown ) ) :time ( z4 have :ARG0 ( z5 bulb ) :ARG1 ( z6 time :ARG1-of ( z7 long ) :purpose ( z8 use :ARG1 z5 ) :ARG1-of ( z9 have-quant :ARG2 ( z10 much ) :ARG3 ( z11 so ) ) ) ) )