The chair is broken,so it is _u________ to sit on

The chair is broken,so it is _u________ to sit on the chair is broken,don't to sit down这句话对吗 the chair is too hard to sit on.改为同义句 the chair i Sit on your chair!Now the chair is ______ you. A dog is on the chair A.sit B.sitting C.siting D.to sit The chair is comfortable to sit on/还是to be sat on? Pam is on the ship.She sit on the chair. the chair is comfortable to sit on为什么要加on? The chair is too dirty to sit on.为什么要加on呢? the chair is soft to ____ 为什么要用SIT ON 不是BE SAT ON chair is comfortable to sit on 还是in ? It is on the chair 对on the chair提问