A (mountain range) can be rugged.Logical formLearned from113 sentences. A scenery can be rugged.Logical formLearned from112 sentences. Features can be rugged.Logical formLearned from107 sentences. Slopes can be rugged.Logical formLearned from106 sentences. Canyons can be rugged.Logical formLearned from100 sentences. Trails can be rugged.Logical formLearned from99 sentences. Highlands can be rugged.Logical formLearned from98 sentences. A cliffs can be rugged.Logical formLearned from97 sentences. A north can be rugged.Logical formLearned from96 sentences. An island can be rugged.Logical formLearned from92 sentences. Men can be rugged.Logical formLearned from91 sentences. A road can be rugged.Logical formLearned from90 sentences. Jungles can be rugged.Logical formLearned from89 sentences. A gorge can be rugged.Logical formLearned from88 sentences. A device can be rugged.Logical formLearned from87 sentences.