A.不存在
B.
C.
D.
[单选题]等于( ).A.不存在B.C.D.
[判断题]A.对B.错
[单选题]A.-48.12kJB.243.06kJC.-240.6kJD.-241.82kJ
[单选题]A.B.C.D.
[单选题]A.1.5RB.3RC.0D.2.5R
[单选题]A.增大B.减小C.不变D.不确定