【正确答案】 A

【答案解析】[解析] border：边界、边疆，例如：They fled across the border．他们穿越边界逃走了。string：绳子，例如：He held out a small bag tied with string．他拿出一个系着细绳的小袋子。spot：地场所，例如：He did not mention having been on the spot．他没说他当时在场。zone：区域，例如：How is the economic development zone going on?现在经济开发区怎样了?