A6. The expression $\sin 20^{\circ}+\sin \alpha$ can be transformed into:
(A) $\cos 70^{\circ}+\sin (\pi-\alpha)$
(B) $\cos \left(\alpha-20^{\circ}\right)$
(C) $\sin 20^{\circ}+\sin (\alpha-\pi)$
(D) $\sin \left(20^{\circ}+\alpha\right)$
(E) $\sin 160^{\circ}-\sin (\pi-\alpha)$

## II. PART
A6. Since $\sin 20^{\circ}=\cos 70^{\circ}$ and $\sin \alpha=\sin (\pi-\alpha)$, it follows that $\sin 20^{\circ}+\sin \alpha=\cos 70^{\circ}+\sin (\pi-\alpha)$.

II. PART