11.   The army crossed the border and advanced on Warsaw.

12.   The two fugitives continue to cross borders.

13.   The UN appealed for help with the flood of refugees crossing the border.

14.   Thousands of people crossed the border, seeking refuge from the war.

15.   We cross the border once or twice a week.

16.   The police were hiding in the bushes, watching for drug smugglers trying to cross the border.

17.   To cross the border, you will need a valid passport.

18.   Troops crossed the border in violation of the agreement.

19.   Our reporter spent the night crossing the border from Austria into Slovenia.

20.   The men lost their way in a sandstorm and crossed the border by mistake.