sweep的过去式是什么

例句：

Wintry weather continues to sweep across Colorado.

寒冬气候继续席卷科罗拉多州。

The rescue helicopter made another sweep over the bay.

救援直升机在海湾上空又搜索了一遍。

strong winds regularly sweep the islands.

这些岛屿上经常刮大风。