Option (A): This is true. The Boolean AND operation with 1 always yields the variable itself: \(x \cdot 1 = x\).
Option (B): This is false. The Boolean OR operation with 1 always yields 1, regardless of the value of \(x\): \(x + 1 = 1\).
Option (C): This is false. The Boolean AND operation with itself yields the variable itself: \(x \cdot x = x\), not 0.
Option (D): This is true. The Boolean OR operation with the complement of a variable always yields 1: \(x + \overline{x} = 1\).
Final Answer:
\[
\boxed{\text{(B), (C)}}
\]