54. An exam consists of six true/false questions, with correct answers marked by $\sqrt{ }$ and incorrect answers marked by $\times$. The scoring method is: 2 points for each correct answer, 1 point for each unanswered question, and 0 points for each incorrect answer. The answers and scores of $A, B, C, D, E, F, G$ are recorded in the table below, then the score of $G$ is _. $\qquad$
Reference answer: 8
Key point: Logical reasoning -- contradiction and elimination