Oxygen is a kind of gas, ________ we couldn’t live．

1. This is the biggest lab ______ we have ever built in our university.
2. Air, ______ we breathe every day, is around us all the time.
3. He is a man of great knowledge, ______ ______ much can be learned.
4. The man, in ______ bag you found your lost money, has been sent to the police.
5. The village has developed a lot ______ we learned farming two years ago.
6. Who ______ has common sense will do such a thing?
7. The reason ______ he didn't come was that he was injured.
8. Oxygen is a kind of gas, ______ ______ we couldn't live.
9. I was surprised at the way ______ he treated the old man.
10. We are living in an age ______ many things are done on computer.