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B/
1. Haven't spoken / went 
2. Have you known 
3. Has been worn 
4. Have already seen / haven't read 
5. Made 
6. Was made 
7. Be found 
8. Were freed / being examined 
9. Will be carried out / be completed 
10. Be carried 
C/
1. I have learned French for two years. 
2. A lot of beautiful trees have been grown in the garden by my grandfather. 
3. This letter should be sent before Sunday. 
4. I have used this computer for 5 months. 
5. You will be invited to their wedding party. 
6. I have moved to this area since 2000.
7. I have never tried this food before.
8. The date of the meeting is going to be changed. 
9. Nothing was done to stop the fire. 
10. Different styles of clothes have been introduced by many designers in the last few years. 
II/
a. Their departure has been put off until next week. 
b. How was the lost girl found by the police? 
c. People make these artificial flowers of silk. 
d. Nothing could be done to stop the fire. 
e. It was thought that he made a big mistake.
f.  I haven't told about the date of the meeting. 
h. Traditional food isn't often eaten by foreign tourists. 
I. The tree near the window will be cut down by my father. 
J. Jane is being asked a lot of questions by the examiner. 
III/
1. English is spoken all over the world. 
2. Christmas is celebrated in many countries in the world. 
3. Tea must be made with boiling water. 
4. Milk bottles are collected and sent to factory to recycle.