单项选择题 鉴别原发性与继发性甲状腺功能减退最佳方法是( )

单项选择题 For m>p2,the demand functions for goods 1 and 2 are given by the equations, x1 = (m/p2)-1 and x2 = p1/p2; where m is income and p1 and p2 are prices. Let the horizontal axis represent the quantity of good 1. Let p1 = 1 and p2 = 2. Then for m > 2; the income offer curve is: A. a vertical line. B. a horizontal line. C. a straight line with slope 2. D. a straight line with a slope of 1/2.

单项选择题 肉新鲜度的理化检验中国家规定的检验项目为挥发性盐基氮，其判断标准为新鲜畜肉、禽肉不得高于多少mg/100g。（ ）。 A.10B.15C.20D.25