TOEFL Reading: ETS-TOEFL阅读机经 - N3ZP338K1894736QL$

What is the role of paragraph 6 in the passage? A. To propose a method for deciding whether a given dam should be removed B. To emphasize the complexity of the issues involved in deciding what should be done about dams C. To suggest that the recent tendency not to build new dams may be wrong D. To sum up the points made earlier in the passage about the advantages and disadvantages of removing dams