10 The museum ..... (visit) by a million people so far.

Passive voice explanation:

• The passive voice is used to show what happens to the subject.
• It is formed with the verb 'to be' (in the correct tense) + the past participle of the main verb.
• 'So far' indicates an action that started in the past and continues to the present, so we use the present perfect passive ('has/have been' + past participle).

Answer:

10 The museum has been visited by a million people so far.