Attempts to restrict parking in the city centre have further aggravated the problem of traffic congestion.
【正确答案】 C
【答案解析】解析:限制市中心的停车场的尝试进一步加剧了交通堵塞问题。划线单词aggravate“使恶化”。ameliorate“改善”,aggregate“合计”,deteriorate“恶化”,duplicate“复制”。故正确答案为C。