We should mind our behaviour ______ public.
| A．at | B．in | C．on | D．out |
The foreigner tried his best, but he still couldn't make his point _______ .
| A．understand | B．understanding | C．to understand | D．understood |
People _______ in the city do not know the pleasure of country life.
| A．live | B．to live | C．lived | D．living |
The _______ price will save you one dollar for each dozen.
| A．reduce | B．reducing | C．reduced | D．reduces |
The student corrected his paper carefully, _______ the professor's suggestions.
| A．follow | B．following | C．followed | D．being followed |
He went from door to door, _______ waste papers and magazines.
| A．gathering | B．gathered | C．gather | D．being gathered |