选出应填入下面一段英语中______内的正确答案。 During the past years, intelligent technology has evolv

选出应填入下面一段英语中______内的正确答案。

During the past years, intelligent technology has evolved(1)three generations. The first was characterized by tools such as Prolog and OPS. Prolog is a simple backward-chaining environment, and OPS is a simple forward-chaining environment.

This led to the second generation of knowledge-engineering environments. Its goal was to model, prototype and construct(2)systems.

All three generations were oriented toward generic(3)and represented generalized implementation environments for the construction of expert system, knowledge based and AI applications.

Some of the solution-oriented products are also seamlessly integrated with generic knowledge-engineering enviroments, permitting users to add(4)rules and objects, as well as predefined knowledge-base logic to address problems in manufacturing simulation.

Marketplace orientation is rapidly(5)toward solution-oriented intelligent product environments. The fourth generation represents a new line of thinking and development by commercial firms will reduce the cost, risk and development time associated with problem solving.

供选择的答案：

(1) software (2) custom (3) control (4) having

(5) shifting (6) search (7) database (8) knowledge

(9) after (10) through (11) problem solving (12) by