1. I can assure you that this box ________ never been opened before I opened this morning.

2. The nights were the worst part for she was haunted by ________ thoughts which were killing her.

3. Her mind was occupied by one ________ thought and that was to leave this family forever.

4. That building ________ left unoccupied since 1950.

5. As the path was very narrow and dangerous, the guide told them they should walk in ________ file.

6. I'll finish now and I look forward to ________ you again soon.

7. Since you have bought a brand new house I think you should insure it for all ________ .

8. Try ________ the door really hard if you want to open it.

9. Pregnant women do not seem to realize that smoking and drinking expose their babies to a serious health ________ .

10. And at other times I'm glad I ________ know what the future holds.