根据题意分析可知，小$$Y$$后面有$$42-22=20$$（人），$$22-20-1=1$$（人）．那么小$$M$$应该在小$$Y$$的正前方，所以小$$Y$$和小$$M$$之间有$$0$$个人．  故选：$$\text{A}$$． 
$$42$$ children are lined up to go on an autumn trip,~ $$Y$$ is the $$22$$th from the front and $$M$$ is the~~$$22$$th from the back of the line. How many children are between $$Y$$ and $$X$$?  $$42$$个小朋友排成一队去秋游，从排头往后数，小$$Y$$是第$$22$$个，从排尾往前数，小$$M$$是第$$22$$个，小$$Y$$和小$$M$$中间有个人． 

A) $$0$$ 
B) $$1$$ 
C) $$2$$ 
D) $$3$$ 
E) $$4$$ 