单选题 Doctors warned sun-starved tourists who received too much sunlight that they were at {{U}}seriously{{/U}} risk than others of contracting skin cancer.
【正确答案】 D
【答案解析】[分析]词语应用 选项A、B是修饰形容词或副词的，选项C词义不对，因此D为答案，表“面临更大的危险”。