Professor Tang didn’t give us a speech today.It was he had a traffic accident on the way to school.
He has given me so much help that I really want to do something for him ______.
“You can’t get this football back ______ you agree not to kick it on my windows again”, he said angrily.
While typing, Helen has a habit of stopping ______ to give her long and flowing hair a smooth.
______ you’ve got a chance, you might as well make full use of it.
As is known to all, the financial crisis firstly broke out in the United States, ______ the group of developed countries.