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关于致心律失常型右心室心肌病，错误的是（）。
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对颅内肿瘤的描述正确的是（）
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至少应间隔多长时间试验一次卫星应急无线电示位标（）
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一般来说，在实测阶段的物料输入总量与输出总量之间的偏差≤5%，则可根据物料平衡结果进行随后的评估与分析。
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Quotas , tariffs and subsidies Like most wars,a trade war may bring about desired economic or political changes, but in the long run almost everyone suffers ,including those whom the trade war was meant to help. An efficient carmaker, for example, may ask for limits of foreign imports, hoping to keep its price high without improving the quality of its products. In the end , however , other countries may retaliate with trade restrictions of their own. Consumers and businesses in both countries are then forced to buy poorly made and expensive domestic products. Trade restrictions might protect a few jobs in inefficient industries,but the whole economy often suffers by becoming less competitive in the international markets. The most common tools for limiting imports of foreign goods and services are quotas, tariffs,and subsidies. When a country imposes a quota, it limits the quantity of certain foreign products that can be imported. A tariff is a tax placed on goods entering a country , raising the price of imported goods. A government can also use the taxpayers' money to provide a subsidy to local producers , making the price of local goods artificially lower than imported goods. Trade barriers, like walls between feuding neighbors, are usually imposed unilaterally by one country acting on its own to limit the amount of foreign products available to local producer from foreign competition and allow them time to improve their products or lower their prices as long as they are protected from foreign competition by trade barriers. Although trade restrictions are of dubious economic value, they have been shown to be effective in bringing about political or social change. The refusal of countries to trade and do business with South Africa, for example, was widely seen to be responsible for the decision to dismantle the system of apartheid. Trade blockades can be useful in forcing countries to change policies that violate human rights or international treaties, but as long as a sufficient number of countries join in the blockade to make it effective. Questions for reading :
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在FeSi中，Si45的密度比（）密度大。
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串联电感的总电感值等于各分电感的（）。
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蛙卵属偏黄卵，其卵裂类型应为（）。
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能发挥调理作用的是（）
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人工自动免疫进入人体的物质是（）。