Given sets $E=\left\{x \left\lvert\, x=\cos \frac{n \pi}{3}\right., n \in \mathbf{Z}\right\}, F=\left\{x \left\lvert\, x=\sin \frac{(2 m-3) \pi}{6}\right., m \in \mathbf{Z}\right\}$. The relationship between $E \sqsubseteq F$ is
(A) $E \subset F$
(B) $E=F$
(C) $E \supset F$
(D) $E \cap F=\varnothing$
1. (B).

Since the functions $x=\cos \frac{n \pi}{3}$ and $x=\sin \frac{(2 m-3) \pi}{6}$ both have a minimum period of 6, taking $n, m=0, 1, 2, 3, 1, 5$, we get $E=\left\{1, \frac{1}{2},-\frac{1}{2},-1\right\}, F=\left\{-1,-\frac{1}{2}, \frac{1}{2}, 1\right\}$.