your son a computer?——No.He one this summer vacation.

Look at ______ book on the desk . Is it ______ useful one ?–Yes, it is . In the book there is much advice on how to learn math well.

Eric, isn’t this book yours?—Yes, it used to belong to _________, but from now on it isn’t.

Welcome the Americansour city.[ ]

We are going to have a party _____ the afternoon_____ December 25th.[ ]