Leave your key with your neighbor ________ you lock yourself out one day.(2012·辽宁)
He has made a discovery, _________ of great importance to the progress of science and technology.
Rosy came in for _________ coffee and told me _________ firecrackers outside kept her awake last night.
—Dad, where on earth did you put my raincoat? —Oh, Jim.I forgot to tell you.It _________ behind your bedroom door.
In autumn, _________ the weather is often cool and fine, people living in the city always like climbing hills for outdoor activities to strengthen their health.
—I telephoned him twice and I couldn’t get through to him. —The line might have been out of order, _________?