they usually sit watching tv. 为什么用watching?

they usually sit watching tv. 为什么用watching? They watching TV Are they watching tv? NO,( ) ( ) they all are watching tv They are watching TV watch为什么要加ing They turn on their TV set to sit ___ them instead watching o They are watching TV now.(用every Sunday代替now) They are usually at home watching TV怎么改否定句 适当形式填空说明为什么1my brother is(sit)on the sofa and watching tv They can learn b______ watching TV They watching TV __ that moment. They are watching TV carefully 变成感叹句