求f’_x(0，0)和f’_y(0，0)．

It is worth looking at one or two aspects of the way a mother behaves towards her baby. The usual fondling, cuddling and cleaning require little comment, but the position in which she holds the baby against her body when resting is rather revealing. Careful studies have shown the fact that 80 percent of mothers hold their infants in their left arms, holding them against the left side of their bodies. If asked to explain the significance of this preference most people reply that it is obviously the result of the predominance of right-handedness in the population. By holding the babies in their left arms, the mothers keep their dominant arm free for manipulations. But a detailed analysis shows that this is not the case. True, there is a slight difference between right-handed and left-handed females; but not enough to provide adequate explanation. It emerges that 83 percent of right-handed mothers hold the baby on the left side, but so do 78 percent of left-handed mothers. In other words, only 22 percent of the left-handed mothers have their dominant hands free for actions. Clearly there must be some other, less obvious explanation.

The only other clue comes from the fact that the heart is on the side of the mother’s body. Could it be that the sound of her heartbeat is the vital factor And in what way Thinking along these lines it was argued that perhaps during its existence inside the body of the mother the unborn baby get used to the sound of the heart beat. If this is so, then the re-discovery of this familiar sound after birth might have a claiming effect on the infant, especially as it has just been born into a strange and frighteningly new world. If this is so then the mother would, somehow, soon arrive at the discovery that her baby is more at peace if held on the left against her heart than on the right.

正确

错误

白酒生产企业销售给销售单位的白酒，生产企业消费税计税价格高于销售单位对外销售价格70%(含70%)以上的，税务机关不再核定消费税最低计税价格

白酒生产企业销售给销售单位的白酒，生产企业消费税计税价格高于销售单位对外销售价格50%(含50%)以上的，税务机关暂不核定消费税最低计税价格

白酒生产企业销售给销售单位的白酒，生产企业消费税计税价格低于销售单位对外销售价格70%以下的，消费税最低计税价格由税务机关根据生产规模、白酒品牌、利润水平等情况在销售单位对外销售价格50%至70%，范围内自行核定

已核定最低计税价格的白酒，生产企业实际销售价格高于消费税最低计税价格的，按实际销售价格申报纳税

已核定最低计税价格的白酒，销售单位对外销售价格持续上涨或下降时间达到3个月以上、累计上涨或下降幅度在20%(含)以上的白酒，税务机关重新核定最低计税价格

正确

错误

只有Ⅰ

只有Ⅱ

都可以

都不可以