zhè / xiē / shì / bīng / cháng / qī / shù / shǒu / biān / jìng / shǒu / hù / zhe / dāng / dì / jū / mín / de / ān / quán这些士兵长期戍守边境,守护着当地居民的安全。These soldiers have guarded the border for a long time, protecting the safety of local residents.