请选择DCBA0D*P.i4j6m/S7A/r No sooner had we reached the top of the mountain _________ we all sat down to rest.-L5P)C/n*l2r
A.when-L5P)C/n*l2r
B.then-L5P)C/n*l2r
C.than-L5P)C/n*l2r
D.until-L5P)C/n*l2r