Smart phones are more and more popular now.—So they are. But they still ________ too much.

There _______an important meeting this afternoon. All of you should attend it.

_______ China implements (实施) its control over the disputed regions, can its sovereigntyand interests be defended.[ ]

Why are you late, dad ––I met a friend and we ____ in the street for a while.

25. I ______ have been more than six years old when the accident happened.