变动成本率与边际贡献率之和为1()
A. 对
B. 错
降低产品销售价格10%与单位变动成本增加10%对利润的影响是一致的()
A. 对
B. 错
有人说风筝的前身是一种能终日飞行的木鸟。但更可能的是斗笠被大风吹起时产生的灵感让古人发明了风筝Legends say that inspiration for kites was a wooden bird flying all day. Most likely, people ____ a hat blown off by the wind and ____ feng zheng
还有些传说古代的将军令人用牛皮作巨大的风筝绑上竹哨. 发出恐怖的声音以瓦解敌方的士气____ also say that a general bound bamboo whistles on a huge feng zheng made of ox hide. The kite made horrible sounds to _____.