【正确答案】 D

【答案解析】[注释] 惯用搭配。gain/make up ground(on)是习语，意为“逐渐追及某人或某事”。例如：1)The police car was gaining ground on the robbers．(警车逐渐追上劫匪。) 2)How can we gain/make up ground on our competitors?(我们如何才能赶上竞争对手?)