It is hard that Tom works out the exercise without your help

It is hard that Tom works out the exercise without your help It is said that he often works-------the clock ,without any It is c that he passed the exam,because he always works hard The math problem is so hard that we ean't work it out. The m In your life, it is s________ very hard to walk out of the p The problem is so hard that almost nobody can work it out为什么 改为同义句I find that it is hard for him to work out the problem. tom never works hard at his lessons,so it is not___to see a The problem is so hard that I can't work it out .如果去掉"it"就不能 Tom works very hard. Without your help,I can't work out the problem He has been a do ,it ,of ,students ,said ,the ,that ,enough,is ,exercise ,