results on almost cohen-macaulay modules

Let (r;m) be a commutative noetherian local ring,and m be a non-zero nitely-generated r-module. we show that ifr is almost cohen-macaulay andm is perfect with nite projectivedimension, then m is an almost cohen-macaulay module. also,we give some necessary and sufficient conditions on m to be analmost cohen-macaulay module, by using ext functors.