Mr Wang often says to her child, "You _______ play with fire (火). It's dangerous.

 [ ]

A. mustn't

B. had better

C. needn't

D. may not

漏电保护器与被保护的用电设备之间的各线（）。

A.不能碰接

B.可以碰接

C.不能分开

D.可以共用