多项选择题 创新的特点是( ) A、新颖性 B、低风险性 C、高回报率 D、综合性
问答题 骨炭是由兽骨燃烧去掉有机质的产品,其主要成分是[填空(1)] 。
单项选择题 Assume that a war reduces a country's labor force but does not directly affect its capital stock. Then the immediate impact will be that: ( )A.total output will fall, but output per worker will rise. B.total output will rise, but output per worker will fall. C.both total output and output per worker will fall. D.both total output and output per worker will rise.