I.
1) Jeans are worn by young people at work
2)Tree leaves are used to wrap things
3)Is English spoken in Canada?
4)These questions were answered quickly by Mai
5)I was kept waiting for half an hour
6)My name isn't known
7)That product wasn't recycled
8)The glass was collected and sent to the factories
II.
1)was cleaned
2)used
3)weren't seen
4)is covered
5)are made
6)was caused