下列对有关主题知识的归纳错误的是
答案：C
A、空气中氮气体积分数为78%，所以氮元素含量最多，地壳中最多的前五种元素是：氧、硅、铝、铁、钙，所以地壳中含量最多的金属元素是铝，故A说法正确；
B、人体缺铁会引起缺铁性贫血，人体缺碘--易造成甲状腺肿大，故B说法正确；
C、铁生锈的条件是铁与水、氧气接触，菜刀防生锈用布包裹，不能隔绝空气和水；煤炉取暖中毒是一氧化碳中毒，由于一氧化碳难溶于水，所以室内放盆水不能防中毒，故C说法错误；
D、白色污染就是指一些塑料垃圾，所以使用可降解塑料可以减少白色污染，乙醇汽油中的乙醇燃烧后没有有害气体，所以使用乙醇汽油可减少汽车尾气污染，故D说法正确．
故选C．
Passage Two
| The idea of building "New Towns" to absorb growth is frequently considered a cure-all for urban problems. It is wrongly assumed that if new residents can be diverted from existing centers, the present urban situation at least will get no worse. It is further and equally wrongly assumed that since European New Towns have been financially and socially successful, we can expect the same sorts of results in the United States. Present planning, thinking, and legislation will not produce the kinds of New Town that have been successful abroad. It will multiply suburbs or encourage developments in areas where land is cheap and construction profitable rather than where New Towns are genuinely needed. Such ill-considered projects not only will fail to relieve pressures on existing cities but will, in fact, tend to weaken those cities further by drawing away high-income citizens and increasing the concentration of low-income groups that are unable to provide tax income. The remaining taxpayers, accordingly, will face increasing burdens, and industry and commerce will seek escape. Unfortunately, this mechanism is already at work in some metropolitan areas. The promoters of New Towns so far in the United States have been developers, builders, and financial institutions. The main interest of these promoters is economic gain. Furthermore, federal regulations designed to promote the New Town idea do not consider social needs as the European New Town plans do. In fact, our regulations specify virtually all the ingredients of the typical suburban community, with a bit of political rhetoric (修辞) thrown in. A workable American New Town formula should be established as firmly here as the national formula was in Britain. All possible social and governmental innovations as well as financial factors should be thoroughly considered and accommodated (容纳) in this policy. Its objectives should be clearly stated, and both incentives and penalties should be provided to ensure that the objectives are pursued. If such a policy is developed, then the New Town approach can play an important role in alleviating America’s urban problems. |
According to the writer, the advocators of New Towns in the U. S. ______.
A．mainly have profit in mind
B．attach importance to social needs
C．hope to relieve pressures on existing cities
D．intend to follow the European example