这条河流形成了两国之间的边界。

This river serves as the ___limit between the two countries.

公园规定每个游客最多带两瓶水。

The park has a ___limit of two water bottles per visitor.

这台电脑的性能已经达到了极限。

This computer is working at its ___limit.

医生建议限制咖啡因的摄入量。

The doctor advised ___limiting caffeine intake.