There are no obvious rules for foot pressure and stitch density.

压脚压力及针迹密度无明显规律。

Whereas Roosevelt knew who the enemy was and what America would have to do, Mr Bush had to choose and name an enemy in a new sort of war without obvious rules, aims or front-lines.

罗斯福知道自己的敌人是谁和美国必需采取怎样的措施去应对，但布什必须选择和指名敌人，而且新型的战争没有明显的规则、目标和前线。

The most obvious challenges to using policy and rules to achieve business goals, is how to demonstrate value to the business from the effort needed to implement policies and rules.

使用策略和规则来实现业务目标所面临的最明显的挑战是如何证明在付出人力实现这些策略和规则后，它能够给业务带来一定的价值。