项目的成功受到许多变量的影响，例如团队协作和资源可用性。

The success of a project is influenced by many ___variables, such as team collaboration and resource availability.

在经济模型中，有许多变量可以影响市场趋势。

In economic models, there are numerous ___variables that can affect market trends.

气候变化是一个复杂的问题，涉及许多相互关联的变量。

Climate change is a complex issue with many interrelated ___variables.