cross a frontier

• 越界

cross a frontier的用法和样例：

例句

1. Was it crossing a line when he invited presidential candidates to hiscrusades or sent along suggestions for their speeches at NationalPrayer Breakfasts?
   当他邀请总统候选人参加他的改革计划或者是直接给候选人在国家祈祷早餐会上演讲的建议是否有些越界呢？