No one ___ philip could work out the difficult problem.

No one ___ philip could work out the difficult problem. no one()philip couid work out the difficult problem This is so difficult a problem as no one can work out.as能不能换 “Can she work out the difficult problem?”the teacher said. ( The maths problem is difficult,but f___we work it out. I find the problem difficult to work out. He is busy to work out the difficult problem. 改错 ____,he can not work out the difficult problem The problem is difficult for me to work out. I find difficult to work out the problem. He found it difficult to work out the problem. The problem is too difficult .------student can work it out