Mum, where did you put my sweater?—Is it _____ black one? I put it in _____orange box near your desk.

Many students wear glasses_____ poor eyesight.[ ]

Distinguished guests and friends . _____the ceremony of the 50th Anniversary this morning are our alumni (校友) from home and abroad .

By the first day of August, 2007, the PLA has its ______ birthday.

I was so busy last year that I was almost mad. So I spent _______ I had with my family last month after I finished the project.