the question is difficult 是主系表还是主谓补?

The question is( ) difficult. the question is difficult to answer The question is very difficult (改感叹句 ) the-----is very difficult,I can not work it out用question 还是p "This is ( )difficult question."the teacher said.A.the more most question is this difficult the连词成句 The question is more difficult to answer _________. It is s_ of you to answer the difficult question. The question is difficult to answer.怎样划分成分? the question is so difficult that only ____students can work The question is so difficult that nobody can answer it The question is ()more difficult than that one