I need help plzz help to find the errors

Dear student , a. 'Were' in place of 'was' b. 'Greater' in place of 'greatest'. c. 'of' in place of 'to' d. 'Working' in place of 'worked'. e. 'becomes' in place of 'became'. f. Can't answer this one as the sentence is incomplete in the given image. Regards