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

单项选择题 广播广告是依附于广播媒体而“开花结果”的一种经营和宣传。从传播方式上看，广播作用于受众的视觉器官，具有快捷、广泛、通俗、悦耳和灵活的特点。（ ） A. 对 B. 错