(2014·石家庄高中复习教学质量检测)Seeing a large crowd at the street corner，I became aware of________unusual happening.

 — Here are three books on history. Which one would you like to borrow?一______. You see, I’m interested in geography these days.

I don’t like the colour of this dress. Could you please show me________ one.

May I have a talk with you , sir ? I have ______important to tell you.

John thought he was ____ when the manager asked him for the advice on the new product.