第一空是定冠词the+可数名词的单数形式.表示类别.第二空是固定词组in danger“处境危险 .类似的零冠词现象的词组有:at war, at peace, at table, at work, at college, at sea, by force, by air, by sea, by train, in bed, in hospital, in peace, in ink, on foot, on sale, on leave, on fire, on business, in public, in secret等. 【查看更多】
