The tomato juice left brown ____ on the front f my jacket．

The government has raised the tax on urban building (房产税) with the ______ of controlling the price of buildings.

I have to reschedule the appointment with you since there is a ______ in my arrangement. 

Please speak in a _______ , or the teacher will hear what you say.

In a(n) _____ to help preserve history, the Greek government established a committee to undertake the professional restoration of the Acropolis.