时态

After analyzing the merit and lack of 9I model, the main idea is proposed: to distill some basic topological relations from 9I model, of which the composite topological relations of complex objects are made up. In detail, the composite topological relationships between region and region, line and line, line and region are particularly discussed;(2)Analyze the characteristics and inner relations of cadastral features. According to the expressional model of complex topological relations, the author discovers the possible topological relations between parcels, parcel lines and parcel points. In addition, sum up the general topological relationship rules of cadastral data.(3) Then the topological relations model is extended to the spatio-temporal data. Time in cadastral database and change semantic are discussed. It's redefined that spatio-temporal topological relations is composed of time, location, status and event relation. Spatio-temporal topological relationships can be represented by extended 4I model. Taking cadastral parcels as example, there are different possible spatio-temporal topological relationships between parcels when they are extended, shrunken, split, merged or others. Thus, some deductions are drawn that, for example, if parcels have be coexisting for some time they are impossible to be overlapped. Furthermore, the parents of parcels alternated and their possible change types can be detected by their spatio-temporal topological relationships.(4) Before carrying out the experiment, the calculation method must be designed.

具体研究工作及成果如下：（1）根据点集拓扑理论中与拓扑空间相关的概念，本文对空间的点、线、面进行了重新定义，以区分对象的复杂性；分析了9I模型在表示简单对象方面的优点，以及在表达复杂对象上的不足，阐述了本文的研究思路和解决方案，并以复杂的面面、线线和线面为例详细探讨了复合拓扑关系的表达方法；（2）分析了地籍权属数据和地类数据的内涵、特点和要素之间的联系，根据复杂对象的拓扑关系表达模型，本文讨论了宗地、界址线、界址点之间，图斑、线状地物、零星地类之间可能存在的拓扑关系和形式化表达方法，归纳总结了地籍对象的拓扑关系满足的约束性规则；（3）将拓扑关系的研究延伸到时空领域，从地籍对象的时态性出发，本文阐述了地籍数据中时间的含义和变化语义描述的需要；从时间、位置、状态、事件等之间的拓扑关系方面，重新系统性地进行了时空拓扑关系的定义；研究了一维时间和二维空间的集成表达方式，以宗地、界址线为例，分析了变更前后不同时间区间里可能的拓扑关系，探讨了时空拓扑关系对时空变化操作类型和变化语义的推理方法和意义；（4）为实现空间拓扑关系的查询分析等应用，本文研究了空间拓扑关系的计算方法。

According to the passage , the present tense in English is not used to express a desire to do something in the immediate future

依照这篇文章，英语中的现在式时态不被用作表达在不远的将来做某事的意愿。

Used to do,be used to sth.／doing sth.

这里的used只能用过去时，不能用其他任何时态。

Not usu in the continuous tenses ;often used with can and could

通常不用于进行时态，常与can could连用

Not usu in the continuous tense s;often used with can and could

通常不用于进行时态，常与can could连用

First of all, the tense of both verbs is in the

首先，这里所用的动词时态是未完成式。

Why does that vowel sound wrong?""

这里用的时态对吗？""

Weak-minded people are not qualified for the post of manager.

主句动词为一般过去时，从句为相对应的过去时态

Hypothetical conditions, marked in English by the backshift of verbs , receive regular treatmentin English grammar.

任何一部英语语法里都有专门的章节阐述假设条件句，因为假设条件句要求动词时态后移然而在汉语语法书里，或者根本不提假设条件这一问题，或者仅仅举例说明有的条件句表达的是与已知事实相反的&纯假设&。

The experiment proves that this model is efficient to index the bitemporal data.

实验证明，利用该模型对双时态数据进行索引是高效的。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。