= Solution
Let the unknown qubit be $|\alpha\rangle=a|0\rangle+b|1\rangle$. Alice holds this qubit and her half of the shared <Bell state> $|\Psi^+\rangle$, while Bob holds the other half.
Alice performs a measurement of her two qubits in the Bell basis and sends the two-bit outcome to Bob through the classical channel. For the shared state $|\Psi^+\rangle$, the <teleportation with the psi-plus Bell state> correction table is
$$
\begin{array}{c|c|c}
\text{Alice's outcome}&\text{Bob's state}&\text{Bob applies}\\ \hline
\Phi^+&X|\alpha\rangle&X\\
\Phi^-&XZ|\alpha\rangle&ZX\\
\Psi^+&|\alpha\rangle&I\\
\Psi^-&Z|\alpha\rangle&Z
\end{array}
$$
up to physically irrelevant global phases. Here $X$ and $Z$ are the <Pauli X gate> and <Pauli Z gate>. After the indicated correction, Bob's qubit is $|\alpha\rangle$. This is <quantum teleportation>; no physical copy of the unknown qubit is sent.
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