In this paper, we first give a sufficient and necessary condition for M = (
A(1)/A(0) I/0) to generate an exponentially bounded (C) over tilde = (C/0 0
/C)-semigroup and discuss its relations to the C-wellposedness of the compl
ete second order abstract Cauchy problem ((ACP(2)) for short) in some sense
. Then we use these results and those in [1] to discuss the C-(exponential)
wellposedness of a kind of (ACP(2)) with application backgrounds, and deve
lop the results in [2].