为什么用stay in bed 不用 on?on不是在 ,之上吗

i stay in bed 为什么用in 不用 on at at不是指小地方吗 He told her to stay in bed ()she recovers.为什么用until不用before 为什么用stay in bed 不用 on?on不是在 ,之上吗 he must stay in bed for a week.这句话中主语是第三人称单数stay为什么不用stays? during my stay in bed 为什么用my,stay为什么用原型 my stay in bed 为什么用my,stay为什么用原型 stay in bed You must stay in bed for other two days.这里为什么要用Another 而不是other? The boy is in the bed .The boy is in the bed.这里为什么不用on 而用in stay in bed还是stay in zhe bed? stay in bed 和stay in the bed的区别 stay in bed 和stay in the bed must stay in bed可以说成stay It is ten o’clock in the morning but Tom is still ( ).in the bed?on bed?in bed?stay bed? stay in bed怎么翻译 stay in bed today是什么意思? stay in bed 汉语是什么 为什么“Don't read in bed.It's bad for your eyes.”这里用“in bed”而不用“in the bed”呢?