1 the bridge which is being built by the workers
2 the professor that you will visit
3 the place where they picnicked last weekend
4 the children whose parents are working somewhere else
5 the reasons why they don't like this course
6 the place where I have worked for 20 years
7 the foreign teacher who is going to teach us English tomorrow
8 the year when he joined the army
9 the courses that the students feel most difficult
10 the village behind which there is a lake
11 the sport which everyone loves
12 a train traffic acident that causes the death of 39 persons