There’s someone knocking on the door. Who _____itbe— Itmust be Mary. She promised to be here at 8：00.

The longest bridge linking Hongkong to Chinese mainland at Zhuhai and Macao in a giant Y- shape, is due to be completed by 2015 and to be in use for 120 years.

I am _______ at the _______ news.

The world’s population is growing ______ and there is _______ land and water for growing rice.

Are you going anywhere for a holiday this summer – Yes, I ______ a plan already.