1. Given the sets $M=\left\{x \left\lvert\, x=\sin \frac{(2 m-3) \pi}{6}\right., m \in \mathbf{Z}\right\}, N=\left\{y \left\lvert\, y=\cos \frac{n \pi}{3}\right., n \in \mathbf{Z}\right\}$, the relationship between $M$ and $N$ is ( )
A: $\quad M \varsubsetneqq N$
B: $\quad M=N$
C: $\quad N \varsubsetneqq M$
D: $\quad M \cap N=\varnothing$
荟叓 B.
Analysis It is easy to know from the periodicity that $M=N=\left\{ \pm 1, \pm \frac{1}{2}\right\}$.