Find the grammar mistakes in the sentences. Write the correct verb forms

1. Linda looks really tired as she
   has worked
   since 5 o'clock in the morning. [ ]

2. Mr Johnson is free now because he

            has been finishing
         the work on the project.  [ ]
   

3. How long

            has Henry studied
         History at the college?  [ ]
   

4. I've just been seeing
   my colleague in the travel agency. [ ]

5. I

            have dusted
   
         the furniture most of the afternoon.  [ ]
   

6. It seems that Kate

            has been being
         in here for many hours.  [ ]
   

7. We

            have discussed
         this issue since the previous month.  [ ]