村民们建造了堤坝来防止河水泛滥。

The villagers built ___dikes to prevent the river from flooding.

他在工作中筑起一道心理防线，不让压力影响到自己。

He built mental ___dikes to prevent work stress from affecting him.

农民们清理了堤坝以确保灌溉水流畅通。

The farmers cleaned the ___dikes to ensure smooth water flow for irrigation.