I _____ the book for two weeks. I must return it to the school library.

al reason why prices ____ , and still are, too high is complex, and no short discussion can satisfactorily explain this problem.

You’d better check the train schedule______ .we have to take a train to Chengdu.

The Expo 2010 Shanghai has not only proved to be a great success but also provided a fantastic model for Milan ________ managing and organizing events of this scale.[ ]

Let ____ help _____.