All over the world the mobile phone has leaped from being an impossible luxury in the early 1980s to        most people would now call a necessity.

We were about to go out for a walk ________ it began to rain.

You needn’t take your shoes off when you enter someone’s house in Australia , _____ , of course , they’re very dirty .

______ he had worked hard all the time, he failed the exam again. 

—How will you deal with these papers, Ann?—I will leave them to ________ takes over the job.