最近或最后获得的信息，对人的社会知觉的影响作用更鲜明、更大，这指的是（）
A.首因效应
B.近因效应
C.晕轮效应
D.心理定势现象
参考答案：B
The population of China is larger than（）of Japan.
A．this
B．that
C．those
D．these
Because copper producers are allowed to release harmful chemicals into the air, the industry supply curve is not the marginal social cost curve. Given this situation and a copper market that is otherwise competitive, copper producers will（）
A. produce less than the efficient amount of copper, an example of the "free rider" problem.
B. produce less than the efficient amount of copper, resulting in a dead weight loss from underproduction.
C. produce more than the efficient amount of copper, resulting in a deadweight loss from overproduction.
