\textbf{47 -- Identify the sentence in which \underline{ليس} has ``nun of protection'':}
\begin{enumerate}
\item[(1)] My friend's words help me to reform myself!
\item[(2)] I say to my colleague: help me in solving this problem!
\item[(3)] My brother wishes to reach the highest levels in knowledge!
\item[(4)] My friend helped me in learning his difficult lessons so I thanked him a lot!
\end{enumerate}