The expected range is short by n minus 1 over n plus 1 and must be inflated

Let $X_{1}, X_{2}, \dots, X_{n} (n \ge 3)$ be a random sample from the uniform distribution on the interval $(\theta_{1} - \theta_{2}, \theta_{1} + \theta_{2})$, where $\theta_{1} \in \mathbb{R}$ and $\theta_{2} > 0$ are unknown parameters. Let $X_{(j)}$ be the jᵗʰ order statistic, j = 1, 2, …, n, and let ${\bar{X}} = (1/n)\sum_{i}$₌$_{1}^{n} X_{i}$. Here, $(X_{(1)}, X_{(n)})$ is a complete and sufficient statistic for $(\theta_{1}, \theta_{2})$. Then, which of the following statements are true?