The mountains form a natural            between the two countries so they have no trade relations in history.

Clothes are just a ________ of money, but one’s real life value lies in his knowledge, morality and quality.

What my wish is to have a round-the-world_______after I retire.

—Sue wants to go to different places, but she doesn’t know the____.—A map will help, I think.

This had a great ____ the future of both mother and son.