His aunt’s letters ________ of those beautiful days when they used to live together in his hometown.
Achieving a high degree of proficiency in English as a foreign language is not a mysterious _____ without scientific basis.
They were so far away that I couldn't _____ their faces clearly.
If the boy had _____ the dog alone it wouldn't have bitten him.
With sufficient scientific information a manned trip to Mars should be _____.
_____ inviting guests and not treating them properly!