单项选择题

What Should Be Taught
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, 1 the jobs must be carried on at the same time. Because we depend so 2 upon science and technology for our progress, we must produce specialists in many fields. 3 we live in a 4 nation, whose citizens make the policies for the nation, large numbers of us must be educated to understand, to uphold, and when necessary, to judge the work of 5 . The public school must educate both producers and 6 of scientific services.
In education, there should be a good balance 7 the branches of knowledge that contribute to effective thinking and 8 judgment. Such balance is defeated by 9 much emphasis on any one field. This 10 of balance involves not only the 11 of the natural sciences, the social sciences and the arts but also relative emphasis among the natural sciences themselves. 12 , we must have a balance between current and 13 knowledge. The attention of the public is continually drawn to new 14 in scientific fields and the discovery of new knowledge; these should not be allowed to turn our attention away from the sound, established materials that form the basis of 15 for beginners.