wèi / le / bǎo / hù / lǎo / lín / yóu / kè / zhǐ / néng / yán / zhe / zhǐ / dìng / lù / xiàn / qián / jìn

为了保护老林，游客只能沿着指定路线前进。

To protect the virgin forest, visitors may travel only along designated routes.