你负责保证你的供货商正确履行合同。为了对合同进行有效的管理，你应该（） A.举行投标
题型：单项选择题
问题：
你负责保证你的供货商正确履行合同。为了对合同进行有效的管理，你应该（）
A.举行投标人会议
B.选举合同的合同形式
C.执行合同变更控制制度
D.准备工作陈述
题型：单项选择题
Marko Tskitishvili, an economist, has been studying the drop in the price of the average household computer in the U.S. and wonders if computers should still be considered a luxury good or if it has now become a normal good. He conducts a survey of 500 people and finds the following:
Assume that 1998 is the base date. Based on the above data, Tskitishvili would conclude that a computer is a:（）
A. luxury good with income elasticity of 1.01.
B. normal good with income elasticity of 0.84.
C. luxury good with income elasticity of 1.18.