1.rahmat has taken a mandarin course

change into passive voice!

1.rahmat has taken a mandarin course 
= a mandarin course has been taken by rahmat

2.they translated some old documents last week 
= some old documents were translated by them last week 

3.the secretary is sending the important emails 
= the important emails has been sent by secretary 

4.well visit our grandmother next week 
= our grandmother will be being visited by us next week 

5.we can see many beautiful paintings in the exhibition 
= many beautiful paintings can be seen by us in the exhibition 

6.they were studying the english lesson when i arrived 
= when i arrived they were studied the english lesson