A year later, Cassin completed his crowning achievement: the first ascent of the Walker Spur of the Grandes Jorasses on the Mont Blanc massif.They reached the summit in 82 hours.是什么意思_A year later, Cassin completed his crowning achievement: the first ascent of the Walker Spur of the Grandes Jorasses on the Mont Blanc massif.They reached the summit in 82 hours.在線翻譯_英語_讀音_用法_例句