Замените следующие действительные обороты страдательными:
1. Who has written this article?
2. The workers are unloading the steamer.
3. The director has just signed the letter.
4. The customs officer is counting the cases.
5. When he entered the room, the legal adviser was checking the contract.
6. The buyers will insure the cargo with "Gosstrakh".
7. As the buyers had not opened a letter of credit, we could not ship the goods.