No, I don’t remember how many years ago _______ I last visited it.

. –Mary, is this ______ umbrella?–No, it’s not mine. It is _______.

Is this __________book?–No．That is ___________ book．

Can I go to the park, Mum?—Certainly. But you ______ be back by six o’clock.

Why did Miss Wang look so worried when we saw her?—Because she wondered .