Which of the following is a statement?

Negation of the statement $(p \vee r) \Rightarrow (q \vee r)$ is :

If $p$ and $q$ each have truth value $F$,then the truth values of the statement patterns $(\sim p \vee q) \leftrightarrow \sim(p \wedge q)$ and $\sim p \leftrightarrow (p \rightarrow \sim q)$ respectively are

The negation of $\sim s \vee (\sim r \wedge s)$ is equivalent to :

The contrapositive of the statement: 'If a function $f$ is differentiable at $a$,then it is also continuous at $a$',is

The negation of the logical statement $(p \vee \sim q) \rightarrow (p \wedge \sim q)$ is