I think the car was invented _____ 1885. [ ]
A. on
B. of
C. at
D. in
答案：D
VisualFoxPro的"参照完整性"中"更新规则"包括的选项是（）。
A.级联、限制和忽略
B.级联和删除
C.级联和限制
D.限制和忽略
