A."數(shù)據(jù)庫"+"系統(tǒng)" B."數(shù)據(jù)庫 "+"系統(tǒng)" C."數(shù)據(jù)庫"-"系統(tǒng)" D."數(shù)據(jù)庫"-" 系統(tǒng)"
A.3 B.1 C.-3 D.-1
A.0 B.7 C.5 D.2