The film was so _____ that soon all the children in the cinema began feeling _____ of it and they went out

one by one. [ ]

A. bored, boring

B. boring, boring

C. bored, bored

D. boring, bored

设有关系模式R(A，B，C，D) ，数据依赖集F=A→B，B→A，AC→D，BC→D，AD→C，BD→C,A→→CD,B→→CD.
1)求R的主码。并判断R是否为第四范式为什么
2)R是不是BCNF为什么R是不是3NF7为什么