Change these active sentences into passive so that they sound more natural
Somebody opened the first car shop in the town in 1992.

The first car shop in the town [ ] in 1992.

1. They have chosen the new marketing plan.

          The new marketing plan          [has been chosen|was chosen|is chosen]                .
   

2. Thousands of workers see this website every day.

                This website                  [has been|was seen|is seen]                by thousands of workers every day.
   

3. The employers asked the staff for their opinions.

                The staff                  [is asked|were asked|had asked]          for their opinions.
   

4. A mechanic is repairing my bike at the moment.

                My bike                  [is being repaired|repaired|is being repairing]          at the moment.
   

5. Somebody has found the missing document.

                The missing document                 [has been found|has found|has been founded].
   

6. Somebody made this clock in Switzerland.

                This clock                  [is made|was made|made]           in Switzerland.