24. The reason ______ he is absent from class is _______ he has caught a bad cold.
Sorry, I have no time left now. Can we discuss the matter ________ supper?
In _______ face of more and more dropout factories, many people prefer to be paid on _____ daily basis.
The manager needs an assistant that he can _____ to take care of problems in his absence.
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.
When talking about China, people often _________ it with the Yellow River.