11.   The first pollution futures market, trading in permits to pollute, has opened for business in Chicago, where the first trade in permits took place last year.

12.   The file must have already been opened for output and the file handle stored in fnum.

13.   You will be unable to open for input if the files not already exist.

14.   If you try to write to a file opened for input you will get a Write protected error.

15.   You will be unable to open for update if the file does not already exist.

16.   The elderly diabetic lady had just been tucked into her bed when the doors were opened for visitors.

17.   She turned to express some of her thanks to him, but he was already out of the car and round by the passenger door opening it for her.

18.   The first big test of government popularity since the General Election comes tomorrow when the polls open for elections to county councils.

19.   A new playroom has opened for children to use while they wait to have artificial limbs fitted.

20.   The house opens for one day on July the thirty first.