答案：D

题目分析：句意：在哥伦比亚，人们不必计划接见朋友。他们经常顺便拜访他们。A. give a ride to 搭车；                    B. give up visiting放弃访问；C. forget to visit 忘记访问； D. come over to顺便来访。根据needn’t make plans to meet their friends可知不用计划去见朋友，意思是朋友会经常来拜访。故选D。