路标给游客指路.Sign posts direct travelers.那位哲人的思想曾是许多青年的指路明灯.The philosopher's thinking was the beacon to many young people.他们把这种理论看作是他们前进的指路明灯.They regarded this theory as a beacon lighting up their advance....

“指路”的英语可以翻译为：show sb.the way;directing the way...