th comes from Australia, but he hasworked in China for five years So you can talk with him ______________

Every possible means ________ to prevent the air pollution，but the sky is still not very clear.

He is a(n) ___________person and he alwayshas many new ideas.

Uncle Bob history books very much.

Where are the students? How could they keep us waiting for so long? –They started an hour ago and they ____ be here in fifteen minutes, I think.