由$$\frac{1}{a-1997}=\frac{1}{b+1998}=\frac{1}{c-1999}=\frac{1}{d+2000}$$，  可知$$a-1997=b+1998=c-1999=d+2000$$，  由这个连等式可得：$$a\textgreater b$$，$$a\textless{}c$$，$$a\textgreater d$$；$$b\textless{}c$$，$$b\textgreater d$$，$$c\textless{}d$$，  由此可得$$c\textgreater a\textgreater b\textgreater d$$，  故选$$\text{C}$$． 
若四个有理数$$a$$，$$b$$，$$c$$，$$d$$满足$$\frac{1}{a-1997}=\frac{1}{b+1998}=\frac{1}{c-1999}=\frac{1}{d+2000}$$，则$$a$$，$$b$$，$$c$$，$$d$$的大小关系是．

[1] $$a\textgreater c\textgreater b\textgreater d$$ 
[2] $$b\textgreater d\textgreater a\textgreater c$$ 
[3] $$c\textgreater a\textgreater b\textgreater d$$ 
[4] $$d\textgreater b\textgreater a\textgreater c$$ 