题目选项分析

Until recently, trade flows were of interest mainly to economic experts and executives of large corporations, but over the past few years, the movement of goods and services across national boundaries has become the subject of intense public attention all over the world.

Until recently, trade flows were of interest mainly to economic experts and executives of large corporations, but since the past few years, the movement of goods and services across national boundaries have become the subject of intense public attention all over the world.