The obliquity of the ecliptic is the fundamental cause of the seasons.黄道的倾角是季节的基本成因.First, we know that the planets all orbit close to the earth's orbital plane, the ecliptic.首先, 我们知道所有行星的轨道都很靠近地球的轨道平面――黄道面.Five bri...
The happiest are not those who own all the best things, but those who can appreciate the beauty of life.最幸福的人们并不一定什么都是最好，只是他们懂得欣赏生活的美好。Young adolescents are happiest with small groups of close friends.青少年在和自己小圈子里的好友呆在一起时...