It was April 29,2001 ____ Prince William and Kate Middleton walked into the palace hall of the wedding ceremony.

The teacher told the students _____in class.

The manager of the travel agency was trying hard to figure out how he would attract more customers ____ an extraordinary idea _____his mind and he immediately knew what to do.[ ]

Thank you very much for showing me how to use the computer.— ________.

Experts think that ____ recently discovered paintingmay be ____ Picasso.