薄冰实用英语语法详解A课程-lesson84

（单词翻译）

7、在一些固定词组中不加冠词。例如：
at home 在家
by mistakes 出错
step by step逐渐
learn by heart 记住
day and night日日夜夜
in sight看见
at first 最初
at last 终于
by chance碰巧
by accident偶然
by way通过
in the face of 面对
In the copy of在复印中
In debt负债
In trouble陷入困境
in place of 取代
on foot徒步
take place 发生
in bed 卧床
in class 课上
after class 课下
in effect 实际上
in hospital 住院
in person 亲自
in return 作为报答
set sail 起航
on fire 在燃烧
out of question 毫无疑问
keep in mind 记在心上
take root 扎根