Answer and Explanation:
1. Between March 21st and September 23rd the Northern Hemisphere experiences three different seasons. These seasons occur according to the inclination of the earth towards the sun, which modifies the incidence of solar rays on the planet and causes changes in seasons in the hemispheres. In the northern hemisphere, March 21st marks the beginning of spring, June 21st marks the beginning of winter and September 23rd marks the beginning of autumn.
2. The oblique rays are not as efficient as the vertical rays because they do not fall directly on the planet earth, but fall like an inclined straight line, which does not allow the earth to receive all the energy they have, but only receive a part . This is different from the vertical rays that fall directly onto the earth with all their energy.
3. The length of day and night is the same all over the world, only on the equinox. This is because the equinox happens all over the world at the same time and every equinox is 12 hours long. In fact, the length of day and night is not exactly the same all over the world, but on the day of the equinox the differences are very small and that is why we can consider that day and night are the same.