请写出歇后语的后半部分（用成语

半个月亮爬上来-----近水楼台先得月；half moon had climbed------the nearest distance can reach the goal.
明月几时有，把酒问青天，不知天上宫阙，今夕是何年------when can reach the goal,unreal to request the truth,doesn"t know the landscape into