2. Noble and lowly
The ends of the earth, the end of the mountain, a day in Sanqiu, nothing grows.
4. The sky is grey, the wilderness is vast, and the wind and grass are low to see cattle and sheep (grassland)
Once you climb to the top of the mountain, you will see that all the other mountains look short under the sky. (Mount Tai)
Leaves fall like a waterfall, while I watch the long river roll forward (the Yangtze River).
Math:
1: Idle speed: 432/8 = 54 km/h.
Set the express speed x and the whole journey s.
5X+54*5=S
8X/S=22/25
D: X=66，S=600。
2. It takes X days for Party A to complete it alone, and Y days for Party B to complete it alone.
Then:1/x+1/y =110.
6/X+4/Y=8/ 15
X= 15 days, Y=30 days.
3. When A reaches the midpoint, it travels 1/3 more than B, so the speed ratio of A and B is 1/2: 1/3 = 3: 2.
Then the speed of A is 65438 per hour+05% of the whole journey.
When A passes the midpoint, the travel time to point C is: 1/6:0. 1=5/3 hours.
Then during this period, the proportion of the whole driving course of A is: 0. 15*5/3= 1/4.
Then the whole length: 25*4= 100 km.
4. let the radius of the circle be x.
Then: π X*X=( 16.56-2X)X/2.
X=2
Then the area of the circle = 3.14 * 2 * 2 =12.56cm2.