单选题Passage 2 indicates that Costanza himself considers the true value of the world's ecosys- tems to be ______.A a subject more for psychologists than economistsB impossible to determineC likely greater than his estimateD independent of the value of human
题目
单选题
Passage 2 indicates that Costanza himself considers the true value of the world's ecosys- tems to be ______.
A
a subject more for psychologists than economists
B
impossible to determine
C
likely greater than his estimate
D
independent of the value of human emotions
E
roughly equal to the value of the gross national product of the United States1