某些固定词组中不用冠词
(1)与by连用的交通工具名称前：by bus乘公共汽车；by car乘汽车；by bike骑/坐自行车；by train乘火车；by air/plane乘飞机；by sea/ship乘船，但take a bus，in a boat，on the bike前需用冠词
(2)名词词组：day and night日日夜夜；brother and sister兄弟姐妹;hour after hour时时刻刻；here and there到处
(3)介词词组：at home在家；in surprise惊奇地；at noon在中午;on foot步行；at night在晚上；on duty值日；at work在工作；on time准时；for example例如；in class在上课；on show展览；in bed在床上
(4)go短语：go home回家；go to bed上床睡觉；go to school去上学；go to work去上班；go shopping/swimming/boating/fishing去买东西/游泳/划船/钓鱼