村民们经常用鸡蛋换取面粉，他们更喜欢这种以物易物的方式。

The villagers often exchange eggs for flour, preferring this ___bartering system.

村民们经常用农产品互相交换，这是一种古老的以物易物方式。

The villagers often practice ___bartering by exchanging farm produce with each other.