(CP (WHPP-1 (-NONE- *OP*)) (CP (IP (NP-SBJ (NN 潜艇)) (VP (PP-PRP (-NONE- *T*-1)) (VP (VA 沉落)))) (DEC 的))) (NP (NN 原因)))
ARG0: 潜艇 ARGM-PRP: 原因 REL: 沉落