Choose the correct options

The exam appeals system in England [is to review|has to be reviewing|is to be reviewed]. The purpose [is to make|is to made|was to be made] it harder to appeal for higher grades. The proposal is that marks [should be only to change| should only be changed|should only change] if an examiner [has made|had made|is made] an error in applying the marking scheme. The Ministry of Education says the system [was to|is to|had been to] focus on errors. Head teachers say they[concern|are concerned|had concerned] about the plan because [if realised, it will make|it can if realised to make|if realised, it has to make] the situation worse. They say marks[can't be changed|can be changed|have to be changed] based on marking scheme alone. They insist that first-time marking [are all important|were all important|is all important]. Last year 90,000 results  [had changed|were changed|are to change] after challenges to grades by graduates. The plan will [make it harder|make it more hard|have been made harder] to challenge grades. [To complain|Having complained|Complaining] will be made less easy.