40. Deserts and high mountains have always been a ______ to the movement of people from place to pla

問題詳情

40. Deserts and high mountains have always been a ______ to the movement of people from place to place.
(A) barrier
(B) fence
(C) prevention
(D) jam

答案：A
難度：適中0.5
統計：A(0),B(0),C(0),D(0),E(0)