theta

例句：

1. 1. The frequency of the waves is given by the formula θ = kc/λ.
   波的频率由公式θ=kc/λ给出。
2. 2. In quantum mechanics, θ represents the phase difference between two entangled particles.
   在量子力学中，θ代表两个纠缠粒子之间的相位差。
3. 3. The measurement of θ allows us to determine the direction and magnitude of the magnetic field.
   测量θ使我们能够确定磁场的方向和大小。