Tom happened to run across Jennie in the park last Sunday.上星期日汤姆在公园中偶然遇见珍妮。We had to run across some open ground, dodging the bullets.我们只得跑过一片空地躲开子弹。The troops had to run across open fields with no cover.部队不得不在没有任何掩护的空地上跑过。Tell your children not to run across the street.告诉你的孩子们不要跑着穿过大街。