Traditionally, college students hold a graduation ceremony to encourage themselves before they on their life jouney.
"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.
Rod loves __________ clocks. However, he never manages to put them together again.