．——There is a lot of smoke coming out of the teaching-building there．——Really?It be a fire,most probably．A．can B．ought to C．have to D．must为什么选ought to不选can.不是表示猜测吗?

．——There is a lot of smoke coming out of the teaching-building there．——Really?It be a fire,most probably．A．can B．ought to C．have to D．must为什么选ought to不选can.不是表示猜测吗?
．——There is a lot of smoke coming out of the teaching-building there．
——Really?It be a fire,most probably．
A．can B．ought to C．have to D．must
为什么选ought to不选can.不是表示猜测吗?

．——There is a lot of smoke coming out of the teaching-building there．——Really?It be a fire,most probably．A．can B．ought to C．have to D．must为什么选ought to不选can.不是表示猜测吗?
有most probably,表明肯定性很大,按预期强弱,这四个由强到弱应该是must ,ought to,have to,can.
但是用must,表示一定,后面的most p就不用了,所以不选.have to 的意思不对,一般用法,sb has/have to do.或 it has to be like this仅此两用法.can 没有ought to语气强.所以综上,选ought