$\sim(\sim p \rightarrow q) \equiv$

Write the following statement in the form "if-then":
$A$ quadrilateral is a parallelogram if its diagonals bisect each other.

The statement $(p \wedge (p$ $\rightarrow q) \wedge (q$ $\rightarrow r))$ $\rightarrow r$ is :

If the truth value of the statement pattern $[p \wedge \sim r] \rightarrow [\sim r \wedge q]$ is False,then which of the following has truth value False?

If $p$: switch $S_1$ is closed,$q$: switch $S_2$ is closed,$r$: switch $S_3$ is closed,then the symbolic form of the following switching circuit is equivalent to:

Which of the following statements is a tautology?