6. We haven't seen each other for _______, though we are in the same city.
If the boy had _____ the dog alone it wouldn't have bitten him.
The generation _____ makes it difficult for parents to understand their children's opinions.
With sufficient scientific information a manned trip to Mars should be _____.
_____ it is a good thing I did not get the post I had applied for, though I must admit that I was disappointed at the time.
The two things are the same in outward form but different _____.