Verified answer

1. be kept  (Present Simple Passive)

2. was built (Past Simple Passive)

3 was being painted (Past Continuous Passive)

4 have already been sold out  (Present Perfect Passive)

5 will be opened (Future Simple Passive)

6 was put out (Past Simple Passive)

7 is made  (Present Simple Passive)

8 was returned (Past Simple Passive)

9 will be sent (Future Simple Passive)

10 has been visited (Present Perfect Passive)