[单选题] 下列设备属于停车场管理系统的出口设备是（ ）。
A. 报警控制器
B. 云台镜头控制器
C. 摄像设备
D. 录像设备

If it were only necessary to decide whether to teach elementary science to everyone on a mass basis or to find the gifted few and take them as far as they can go, our task would be fairly simple. The public school system, however, has no such choice, for the two jobs must be carried on at the same time. Because we depend so heavily upon science and technology for our progress, we must produce specialists in many fields. Because we live in a democratic nation, whose citizens make the policies for the nation, large numbers of us must be educated to understand, to support, and when necessary, to judge the work of experts. The public school must educate both producers and users of scientific services.
In education there should be a good balance among the branches of knowledge that contribute to effective thinking and wise judgement. Such balance is defeated by too much emphasis on any one field. This question of balance involves not only the relation of the natural sc
A. students should learn more up-to-date knowledge
B. good balance in education means the proper relations between producers and users of scientific services
C. students are getting to know the importance of a good balance among the branches of knowledge
D. attention is not sufficiently given to basic knowledge