It was April 29, 2011 ______ Prince William and Kate Middleton walked into the palace hall of the wedding ceremony.

Male nurses are difficult to hire as many men reject this______ out of the long-existing discrimination.

Tom in the library every night over the last three months.

This naughty boy is really ________,which makes his mother upset. [ ]

下列各句中，没有语病的一句是