Fill in for or since into the gaps. 1. Nobody has seen him ___ last Friday.
2. It has been foggy ___ some days.
3. He has been fishing ___ six o'clock.
4. They've been living in France ___ eight years.
5. The pilots have been on strike ___ two months.
6. We've had terrible weather ___ Saturday.
7. I've known Tom ___ 1990.