The first sentence. This is the vertical difference of climate. The temperature decreases with the elevation. Every altitude 100 meters, the temperature drops by 0.6 degrees Celsius. The temperature on the mountain is naturally lower than that under the mountain, and the flowering period is also late. The vertical climate of the mountain and Bai Juyi's poem in Tang Dynasty: "In April, flowers bloom on the mountain temple. It vividly reflects that the temperature decreases with the elevation. Vertical differences of phenology in mountainous areas. Normally, the temperature drops by 0.6℃ for every elevation increase of 100 m. The elevation of Dalin Temple in Lushan Mountain is between1100 ~1200m, which is about 6℃ lower than that of (flat land in Jiujiang City, with an average elevation of 32m). So the time of peach blossom is 20% behind.
The second sentence. It is the reason why China is high in the west and low in the east that makes the water flow from west to east. "Gone forever" is correct on the surface, but the process of water circulation is not like this. There is a land-sea cycle, or a big cycle. After the land water reaches the ocean, the water in the ocean evaporates and is replenished to the river through the precipitation on the land. Without this process, the river would have dried up long ago.