--You don't look so well, Mary. What's the matter with you? --Why?___________.
I hope that the little ________ I have been able to do does good to them all.
There are several research centers in China ________ a certain disease called Bird Flu is being studied.
The treatment will continue until the patient reaches the point ________ he can walk correctly and safely.
October 15 th is my birthday, ________ I will never forget.