By the first day of August, 2007, the PLA ________ for eighty years.

Jack, when shall we go to visit Mr. Smith? – It’s up to him. We’ll go to see him whenever _______.

Must I use both hands?-Yes, you _____.

Is that your best friend Kitty?— No, it _________ be her. She flew to Singapore yesterday.

_____ does your English teacher teach you English songs?—Once a week.[ ]