It"s satuday afternoon ,they ought to be back home .为森么ought to 要加个be

It"s satuday afternoon ,they ought to be back home .为森么ought to 要加个be
It"s satuday afternoon ,they ought to be back home .为森么ought to 要加个be

It"s satuday afternoon ,they ought to be back home .为森么ought to 要加个be
主要是to决定的 to是动词不定式 后面要加动词的原型,而back是副词天使修饰动词的

ought to应该，后接动词原形，所以用be.
又如：He ought to do my homework now.
希望能帮到你~