Complete the sentences with the correct passive form of the verbs in brackets. 1. This skirt ... (make) from silk. 2. A lot of dogs ... (abandon) in the streets by their owners. 3. All the concert tickets ... (already/ sell out) . 4. This book ... (return) to the library next week. 5. When ... (build) the Eiffel Tower? 6. The building ... (finish) last month. 7. Photography ... (not, allow) in the museum. 8. The Leaning Tower of Pisa ...(cover) in marble.

Here are the answers with explanations: 1. This skirt is made from silk. *Explanation:* The skirt is being described in the present, and it is being acted upon (made). Therefore, the present simple passive form is used: 'is made'. 2. A lot of dogs are abandoned in the streets by their owners. *Explanation:* The sentence describes a general truth, and dogs are the object of the action (abandoned). The present simple passive form is used: 'are abandoned'. 3. All the concert tickets have already been sold out. *Explanation:* The tickets have already been sold by now. The present perfect passive form is used: 'have already been sold'. 4. This book will be returned to the library next week. *Explanation:* The action of returning the book will happen in the future. Future simple passive form is used: 'will be returned'. 5. When was the Eiffel Tower built? *Explanation:* The Eiffel Tower was built in the past. Past simple passive in a question form: 'was built'. 6. The building was finished last month. *Explanation:* The building was finished in the past. Past simple passive form is used: 'was finished'. 7. Photography is not allowed in the museum. *Explanation:* This is a general rule. Present simple passive form is used with a negation: 'is not allowed'. 8. The Leaning Tower of Pisa is covered in marble. *Explanation:* It's a present state. Present simple passive form is used: 'is covered'.