Question

Complete the sentences. Write "for" or "since". 

1. I've been part of the fossil research team _________ three months.

2. Jason hasn‘t written any research articles _________ he became a professor.

3. Penny has been a member of the Science Club _________ two years.

4. The museum has had the skeleton on display ___________1998.

5. Archeologists have known about the footprints in the cave __________ six months.

6. Researchers haven't discovered any fossils in the area __________ last year.