There is a famous saying in ancient China: "A good medicine tastes bitter and is good for illness, but advice when unpleasant is good for action." Tell us to listen to other people's suggestions or opinions, and ""makes us If you want to know what happened in the mountains, you must ask the messenger, so that we can understand and practice by ourselves.

In the warm spring breeze, the heavy rain in midsummer and the cold in late autumn, we can't see any special prosperous period, nor can we see any special declining period. This sentence says that oleander has a long flowering period and its toughness is commendable.