单项选择题
A.5=a+b B.b=a+7 C.b=2*π*r D.2a=b
A.Dim x AsInteger B.Dim x AsInteger，y As Long C.Dim x AsDouble D.Dim x AsSingle，y As Integer
A.机器语言B.汇编语言C.高级语言D.C语言