单项选择题 某代理人接受交易一方的委托与对方代表会谈，而委托人并不出席谈判现场。随着谈判的进行，对方代表作出一个又一个承诺，而等到对方要求该代理人作出相应承诺时，他却以委托人未到为由而委婉地拒绝了。这样他以一个代理人的身份为委托人争取到了对方的许多让步，而几乎没有付出任何代价。A.己方让步B.使对方让步C.阻止对方进攻

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.