zhèng fǔ / zài / shàng yóu / xiū jiàn / le / yī zuò / dà xíng / lán hóng bà / yǐ / bǎo zhàng / xià yóu / jū mín / de / ān quán

政府在上游修建了一座大型拦洪坝，以保障下游居民的安全。

The government built a large flood control dam upstream to ensure the safety of downstream residents.