网络成瘾的心理机制比较复杂，有需要、动机等动力因素和抑郁、孤独、自制力差等人格特质因素。专家认为，体育锻炼作为网络替代品在满足个体需要过程中与人格关系密切。据报道，与不锻炼的人相比，经常参加体育锻炼的人有较强的自制力，他们更聪明、认真、富有想象力、有较强的自立能力。不仅如此，体育运动还可以产生短期心理健康效应。对这段文字的主旨概括最准确的是()。

A．评价体育锻炼对人格培养的重要意义

B．指出体育锻炼作为网络替代品的可能性

C．阐述体育锻炼对治疗网络成瘾的价值

D．说明体育锻炼具有促进心理健康的基本功能

While most recent attention in the AI field has been focused on expert system software, AI (66) has also seen dramatic advances. Activity in the past years was characterized by new low-cost, powerful Lisp machines, the introduction of AI workstations, Lisp compilers becoming available for all major professional and engineering workstations, and the personal computer emerging as a (67) . tool for expert system development. The next few years will see this technology evolves further.
Because the (68) of an AI computer represents a sizable investment, companies should carefully (69) all options that are available as well as have a good idea of what the next generation of systems will offer in order to (70) the optimum system. This publication provides the information necessary to gain this understanding.

A．choice

B．read

C．important

D．software

E．hardware

F．significant

G．emergence

H．survey

I．purchase

J．select