it is hard to believethat从句句子成分是不定式做主语还是从句做主语

It is hard to It is hard to wait It is hard to please It is hard to select! It is hard to study English g______well. it is time to study hard! why it is so hard to do It is hard to bear with criticism. it is hard to say 什么意思? It is hard to be a soldier. 是i find it hard to say 还是i find it is hard to say I found it hard to understood为什么不是I found it is hard to understood it is hard to+Ving还是to do sth to explain it to him is hard同义句 ‘It is hard to reciprocate equal love to each other. it is too hard For a time his grandmother found ___accept his new idea.A.hard B.it hard C.it is hard to D.it hard to it is hard to say goodbye同义句 _ _ _ is hard