( This ( ( is ( because ( ( ( the ( light rays ) ) ( ( reflecting off ) ( a plane ) ) ) ( ( mirror never ) ( ( ( converge , ) ( the ( major criterion ) ) ) ( for ( creating ( a ( real image ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (SBAR (IN because) (S (NP (NP (DT the) (JJ light) (NNS rays)) (VP (VBG reflecting) (PRT (RP off)) (NP (DT a) (NN plane)))) (VP (VBP mirror) (ADVP (RB never)) (VP (VB converge) (, ,) (NP (DT the) (JJ major) (NN criterion)) (PP (IN for) (S (VP (VBG creating) (NP (DT a) (JJ real) (NN image)))))))))) (. .)))
This is because the light rays reflecting off a plane mirror never converge, the major criterion for creating a real image .
(ROOT (S (NP (NNP Plane) (NNS mirrors)) (VP (VBP work) (SBAR (IN because) (S (NP (DT the) (JJ light) (NNS rays)) (VP (VBP create) (NP (NP (DT a) (JJ virtual) (NN image)) (PP (IN behind) (NP (DT the) (NN mirror)))))))) (. .)))