"why is your mother   --------?"  
"she is ill"
A  on the bed   B  in the bed  C  on bed   D   in bed

D in bed

in bed

in bed

<P>谢谢</P>

in bed
on the bed

是in bed或on the bed

D in bed

求教：turn on(turn off)    与open (close)有什么区别？:)