Chemicals in the body ______our food _____ into useful things．
| A．break, into | B．break, up | C．break, down | D．break, off |
Geography is the study of the countries of the world and of such things ______ the land, seas, climate, towns, and population.
| A．as | B．that | C．which | D．what |
Late again! What’s your ______ this time?
| A．expression | B．saying | C．meaning | D．excuse |
The professor was so ______, hardly anyone came to class.
| A．popular | B．boring | C．friendly | D．lively |
Jake’s passed his exams. We’re going out to ______.
| A．joke | B．invite | C．celebrate | D．argue |
We couldn’t understand: what could ______ his sudden change of mind?
| A．enjoy | B．explain | C．accept | D．mean |