問題詳情
【題組】66. National parks like Yosemite in the U.S. find it increasingly difficult to meet the need of visitors because ________.
(A) their transport management needs improving
(B) they spend too much on their service systems
(C) their service systems frequently go out of order
(D) they need help from environmental organizations
參考答案
答案：C
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)