送交者: mangolasi 于 2006-1-10, 06:39:28:
回答: 早晨--seriously doubt it. 由 mangolasi 于 2006-1-10, 06:36:15:
the highest point of fresh air (just before the sunset), but not that relevant for the lowest point (as long as the trees give out more oxygen than taking).
The morning just before the sunrise must be the lowest point for the night, and very likely to be the lowest for the 24-hour round (unless there is some pathological points during the daytime.)