资料题：The passage is mainly concerned with（  ）。

A popularly-held view has it that “opportunity to learn” is the key to educational success,i.e., the more time children spend on a subject, the better they do at it. Alas, the evidence so far is not encouraging for the proponents of this theory. According to a recent study，there seems little correlation between time spent on a subject and performance of pupils in tests. Young Austrians spend exceptionally long hours on math and science lessons;for them, it pays off in higher test scares. But so do New Zealand’s teenagers and they do not do any better than, say, Norwegians, spend an unusually short time on lessons in both subjects. Next and of particular interest to cash-strapped governments there appears to be little evidence to support the argument,often heard from teachers' unions,that the main cause of educational underachievement is under finding. Low-spending countries such as South Korea and the Czech Republic are at the top.High-spenders such as America and Denmark do much worse. Obviously, there are dozens of reasons other than spending why one country does well, another badly, but the success of the low-spending Czechs and Koreans does show that spending more on schools is not a prerequisite for improving standards.Another article of faith among the teaching profession that children are bound to do better in small classes is also being undermined by educational research. the study found that France,America and Britain, where children are usually taught in classes of twenty-odd,do significantly worse than East Asian countries where almost twice as many pupils are crammed into each class.Again, there may be social reasons why some countries can cope better with large classes than others.All the same,the comparison refutes the argument that larger is necessarily worse.Further, the study even cast some doubt over the cultural explanation for the greater success of East Asia:that there is some hard-to-define Asian culture, connected with parental authority and a strong social value on education, which makes children more eager to learn and easier to teach.Those who make this argument say it would of course be impossible to replicate such oriental magic in the West.Yet the results of die study suggest that this is, to put it mildly, exaggerated. If “culture”makes English children so poor at math, then why have they done so well at science (not far be-hind the Japanese and South Koreans)? And why do English pupils do well at science and badly at math, while in France it is the other way around? A less mystical, more mundane（世俗的）explanation suggests itself: English schools teach science well and badly; French schools teach math than science; East Asian schools teach both subjects well。