The main reason for the wall's construction had always been defense. Since China's first dynasty, the empire faced a near-constant threat of attack from the nomadic tribes to the north. This included those famed Mongols as well as lesser-known groups like the Xiongnu and the Göktürks.
Answer:
March equinox is day during the year when all the daylight of the sun is asme at sunrise and sunset.
Explanation:
- Equinox is the time when the plane of the earth passes through the centre of the sun. Occurring around 23 March and 23 Sept. The vernal equinox is also called as the spring equinox.
- The azimuth of the sun is the angle of the sun's position defined by the relative direction along the horizon. However the most commonly followed convection for analyzing the sun radiation is 90 degrees east, south 180 degrees and west is 270 degrees.
- As sunrise and sunset are defined by the upper limb of the solar disk. These conditions produce patterns of night and day as the sun appears to move just above the horizon at an angle of 0.39 degrees per day as the equinox passes.
Answer:
because time period does not depend upon the weight of the world
Answer:
none of the above is answer
Explanation:
may be this is helpful!
Answer:
1.to protect people to any virus and to look attractive
2. to maitain a good system and good condition
3.on the cleaniest place and have good air
