A useful theory, in addition to explaining past observations, helps to predict events that have not as yet been observed.
一个有用的理论，除了能够解释过去的观测，还有助于预测那些未被观测到的事件。
2
In addition, the system can also forecast the danger state of certain unit by grey prediction theory.
除此之外，本系统还可以用灰预测理论对某一单元的危险状态进行预测。
3
In addition, as tourism planning is a new field, theory always falls behind practice and an integrated planning theory system has not been established.