【多选题】(多选题)古典园林的理水之法,理论上有( )三种。
【单选题】Suppose that elementary education creates a positive externality. If the government does not subsidize education, then
A.
a. the equilibrium quantity of education will be equal the socially optimal quantity of education.
B.
b. the equilibrium quantity of education will be greater than the socially optimal quantity of education.
C.
c. the equilibrium quantity of education will be less than the socially optimal quantity of education.
D.
d. There is not enough information to answer the question.
【简答题】试述大气中的主要污染物有哪些?并谈谈其主要来源及产生的危害。
【单选题】Suppose the Chinese government regulates the price of food and forbids firms from setting a higher price. In this case the government is setting a
【多选题】根据《联合国国际货物销售合同公约》规定,构成一项有效发盘的条件是()