他小心地移动着黄色路障。

He is carefully moving the yellow ___barrier.

工人们在道路上设置了障碍物以防止车辆进入。

Workers placed a ___barrier on the road to prevent vehicles from entering.

语言障碍常常使国际交流变得困难。

The language ___barrier often makes international communication difficult.

语言障碍常常成为国际交流的边界。

Language ___barriers often serve as boundaries in international communication.