8. Let $\theta_{1}, \theta_{2}, \theta_{3}, \theta_{4}$ be angles in the first, second, third, and fourth quadrants respectively, all between 0 and $2\pi$. Given that $|\cos \theta_{1}| = |\cos \theta_{2}| = |\cos \theta_{3}| = |\cos \theta_{4}| = \frac{1}{3}$, which of the following options are correct? (1) $\theta_{1} < \frac{\pi}{4}$ (2) $\theta_{1} + \theta_{2} = \pi$ (3) $\cos \theta_{3} = -\frac{1}{3}$ (4) $\sin \theta_{4} = \frac{2\sqrt{2}}{3}$ (5) $\theta_{4} = \theta_{3} + \frac{\pi}{2}$
& 2，3 & & 20 & 2 & \multirow{3}{*}{H} & 30 & 2
8. Let $\theta_{1}, \theta_{2}, \theta_{3}, \theta_{4}$ be angles in the first, second, third, and fourth quadrants respectively, all between 0 and $2\pi$. Given that $|\cos \theta_{1}| = |\cos \theta_{2}| = |\cos \theta_{3}| = |\cos \theta_{4}| = \frac{1}{3}$, which of the following options are correct?\\
(1) $\theta_{1} < \frac{\pi}{4}$\\
(2) $\theta_{1} + \theta_{2} = \pi$\\
(3) $\cos \theta_{3} = -\frac{1}{3}$\\
(4) $\sin \theta_{4} = \frac{2\sqrt{2}}{3}$\\
(5) $\theta_{4} = \theta_{3} + \frac{\pi}{2}$