There seems to be no one on the empty mountain, but I think I heard a voice. -Wang Wei's Chai Lu
3, see Wan Shanhong, Lin Jinran. -Mao Zedong's "Qinyuanchun Changsha"
4, after the bleak farewell, the two should be the same, and at most they can't clear their grievances. -Nalan Xingde's Meet Again in the Deep of Qulan.