2. Inch hair worries China: "Inch hair" refers to hair. According to the meaning of the next sentence, "worrying about China" should be understood as not knowing how to pass the time. Time is a feeling of "passing the day like a year" to me.
3, looking at the moon: looking at the moon, I think the moon and I are very lonely.
4. Only envy the mandarin ducks but not the immortals: At this moment, I mean envy the mandarin ducks in pairs, not envy the immortals for a lifetime.
This poem expresses the author's lonely and sad love feelings.