The marginal cost of an activity is the（）
A. change in the total cost of the activity that results from carrying out an additional unit of the activity
B. change in the level of the activity divided by the change in the cost of the activity
C. the total cost of the activity divided by the change in the level of the activity
D. the total cost of the activity divided by the level of the activity
查看答案
The marginal benefit of an activity is the（）
A. total benefit of an activity divided by the level of the activity
B. same as the total benefit of an activity
C. total benefit associated with an extra unit of the activity
D. extra benefit associated with an extra unit of the activity
The number of U.S. households with access to the Internet is growing rapidly. Compared to 50 years ago, one would predict that when considering a major purchase, people today will gather（）
A. more information because the Internet has increased the cost of gathering information
B. less information because the Internet has increased the benefit of gathering information
C. more information because the Internet has lowered the cost of gathering information
D. less information because the Internet has lowered the cost of gathering information
Which of the following would not be studied in macroeconomics（）
A. The growth rate of the U.S. economy
B. How a sharp increase in gasoline prices is likely to affect SUV sales
C. The impact of government spending on the economy
D. The causes of the Great Depression
The Cost-Benefit Principle indicates that an action should be taken if（）
A. its average benefits exceed its average costs
B. its extra benefit is greater than or equal to its extra cost
C. its total benefits exceed its total costs
D. its net benefit （benefit minus cost） is zero
微信支付 
支付宝支付