The practice of hanging clothes across the street is a common _________ in many parts of the city.
I didn't want to go with him, so I invented a (n) __________ about things I had to do on Friday.
"The final exam is coming. You'd better concentrate ___________ your study. " Mother informed me __________ it.
The shop was not far from here, so they went there on foot __________ by bus.
We will do it ourselves __________ asking others to help.
Briggs will __________ as general manager when Mitchell retires.