Change from active into passive voice. 1.she has just posted those letters. 2.the teacher has already checked my test 3.he has just opened all the windows. 4.we have already bought the present. 5.i have just done this exercise. 6.they have already found the key. 7.somebody is cooking dinner in the kitchen. 8.when i came, somebody hase broken the vase. 9.somebody was writing the letters at 5 o`clock. 10.they are laying the table at the moment. 11.somebody has taken the chairs from the classroom. 12.he is teaching now. 13.they had caughtthe fish before we arrived.

1) Letters have been posted by her.
2) My test has been already checked by teacher
3) All the windows have been opened by him
4) The present have been already bought by us
5) This exercise has been just done by me
6) The key has been already found by them
7) Dinner is being cooked by somebody
8) The vase has been broken by somebody when I came
9) The letter was being written by somebody at 5 o`clock
10)The table is being laied by them  at the moment
11) The chairs have been taken from the classroom by somebody
12) невозможно сделать пассив, возможно, предложение написано неверно
13) The fish had been caught by them befor we arrived