Four Seasons, 四季, 四个季节, sì jì, sì gè jì jié。
Spring, 春, 春天, 春季, chūn, chūn tiān, chūnjì。
I like spring., 我喜欢春天。, wǒ xǐ huān chūn tiān.。
We participated in the spring fair., 我们参加了春季展览会。, wǒ men cān jiā le chūn jì zhǎn lǎn huì.。
Summer, 夏, xià。
Food must be refrigerated in summer., 食物在夏天必须加以冷藏。, shí wù zài xià tiān bì xū jiā yǐ lěng cáng.。
Autumn, 秋, qiū。
In autumn, leaves fall from the trees one after another., 秋天，树叶纷纷从树上掉下来。, qiū tiān, shù yè fēn fēn cóng shù shàng diào xià lái.。
Winter, 冬, Dōng。
This work will stop in winter., 这项工作将于冬天停止。, zhè xiàng gōng zuò jiāng yú dōng tiān tíng zhǐ.。
四季，指一年中交替出现的四个季节，即春季、夏季、秋季和冬季，每季三个月。一年四季是因为地球在围绕太阳公转而形成的。由于黄赤交角的存在，造成太阳直射点在地球南北纬23°26′之间往返移动的周年变化，从而引起正午太阳高度的季节变化和昼夜长短的季节变化，造成了各地获得太阳能量多少的季节变化，于是形成四季的更替。
Four seasons refer to the four seasons that occur alternately in a year, namely spring, summer, autumn and winter, each for three months. The four seasons of the year are formed because the earth revolves around the sun. Due to the existence of the yellow-red angle, the annual change of the direct sun’s point moving back and forth between the north and south latitudes of the earth at 23°26′, which causes seasonal changes in the height of the sun at noon and seasonal changes in the length of day and night. The seasons change, thus forming the alternation of the four seasons.
上古时代以斗柄指向确定季节交替，北斗七星循环旋转，这斗转星移与季节变换有密切关系。现划分季节通常是以地球围绕太阳公转轨道上位置确定。四季轮换，反映了物候、气候等多方面变化规律，春生、夏长、秋收、冬藏。我国南方地区（低纬地区），多雨、多风暴、光照充足，季节转换时降雨量、风暴、光照等变化明显；北方地区（中纬地区），少雨、少风暴，季节转换时变化明显的是气温。
In ancient times, the direction of the handle of the bucket was used to determine the alternation of the seasons, and the Big Dipper revolved in a circle. The current seasons are usually determined by the position of the earth on the orbit of the sun. The rotation of the four seasons reflects the changing laws of phenology and climate, including spring growth, summer growth, autumn harvest, and winter storage. Southern China (low-latitude areas) has more rain, more storms, and sufficient sunlight. The changes in rainfall, storms, and sunlight are obvious during the seasonal transition; in the northern areas (mid-latitude areas), there is less rain and less storms. The obvious changes during the seasonal transition are Temperature.
四季的递变全球不是统一的，北半球是夏季，南半球是冬季；北半球由暖变冷，南半球由冷变热。昼夜长短和太阳高度，在不同季节有周期性变化规律。当地球在一年中不同的时候，处在公转轨道的不同位置时，地球上各个地方受到的太阳光照是不一样的，接收到太阳的热量不同，产生季节的变化和冷热的差异。地球上的四季不仅是温度的周期性变化，而且是昼夜长短和太阳高度的周期性变化。它影响或者决定地球环境中很多事物的运动节律，尤其是生物适应最为明显。季节转换涵盖了气候变化、物候变化等多方面特征。四季的周期变化，也标示着事物的发展过程，春天萌生、夏天滋长、秋天收获、冬天储藏。
The evolution of the four seasons is not uniform throughout the world. The northern hemisphere is summer and the southern hemisphere is winter; the northern hemisphere changes from warm to cold, and the southern hemisphere changes from cold to hot. The length of day and night and the height of the sun have periodic changes in different seasons. When the earth is in different positions of the revolution orbit at different times of the year, the solar light received by various places on the earth is different, and the heat received from the sun is different, resulting in seasonal changes and differences in cold and heat. The four seasons on the earth are not only periodic changes in temperature, but also periodic changes in the length of day and night and the height of the sun. It affects or determines the movement rhythm of many things in the earth’s environment, especially the most obvious biological adaptation. Seasonal transition covers many aspects such as climate change and phenological change. The cyclical changes of the four seasons also indicate the development process of things: spring sprouts, summer growth, autumn harvests, and winter storage.