--Is everything we need to do ?
--Yes. You needn’t worry about it.
A. which; has done
B. which; doing
C. that; has done
D. that; done
网友回答
A. which; has done
B. which; doing
C. that; has done
(答案→)D. that; done
解析：本题考查定语从句。在定语从句中，当先行词是everything时，关系代词用that。句意：——这是我们所需要做的一切么？——是的，你们不必担心。