De-normalizing Query

I have this table...

CREATE TABLE #Test (ID char(1), Seq int, Ch char(1))
INSERT #Test SELECT 'A',1,'A'
INSERT #Test SELECT 'A',2,'B'
INSERT #Test SELECT 'A',3,'C'
INSERT #Test SELECT 'B',1,'D'
INSERT #Test SELECT 'B',2,'E'
INSERT #Test SELECT 'B',3,'F'
INSERT #Test SELECT 'B',4,'G'

....and am searching for this query....

SELECT ID, Pattern=...?? FROM #Test....??

....to give this result, where Pattern is the ordered concatenation of
Ch for each ID:

ID Pattern
A ABC
B DEFG

Thanks for any help!

Jim