The earth is an oblate spheroid - a sphere with flattened poles and a slight bulge at the equator.

    The earth's polar diameter is 12,640 km, while its equatorial diameter is 12,683 km. Its equational circumference is 39.842.72 km.

    As the earth rotates, its side that is lighted by the sun is day time, while its side that is in darkness is night time.

    The earth rotates in counterclockwise direction or from west to east. Hence, we see the sun rise in the east.

    The earth rotates at the speed of 1,680 km per hour or 28 km per minute.

    The axis of the earth is tilted 23.5 degrees. Because of this tilt, the hours of day and night are not exactly 12.

    A revolution is the journey of the earth around the sun. The imaginary path followed by the earth is its orbit.

    It takes the earth 365 1/4 days to make one revolution. The period of time it takes a planet to complete one revolution is called a year.

    The earth is revolving at a speed of 105,600 km per hour or 1,760 km per minute.

    The orbit of the earth is elliptical. The point in the orbit nearest the sun is called perihelion, while the point farthest is called aphelion. The average distance of the earth from the sun is 148,800,00 km.

    Seasons occur because the tilt of the earth's axis. In the Northern Hemisphere, the summer has longer days and shorter nights. During winter, there are shorter days and longer nights. The opposite occurs in the Southern Hemisphere.

    The globe is a model of the earth. The top of the globe is North, its bottom is South, its left side is West, and its right side is East.

    The lines drawn from the North Pole to the South Pole are called meridians. The line drawn from the West to East are called parallels.

    The distances measured in degrees north or south of equator are called latitude. Longitude is the distance measured in degrees east or west of the prime meridian.

    The prime meridian is at 0 degrees longitude, and the international date line is at 180 degrees. The equator is at 0 degrees latitude.

    To find the exact location of a place at the globe, find its latitude and longitude.

    A map is a flat or graphic representation of the earth's surface. The art of map making is called cartography.

    To read a map, take note of the compass direction, the legend, and the reference lines.

    The 24 time zones on the earth correspond to the 24 meridians drawn on the globe at 15 degrees intervals.

    The calendar shows the 12 months of the year. September, April, June, and November have 30 days, and the other months have 31 days, except February, which has 28 days.

    地球是一個扁平的球體--一個具有扁平的兩極和赤道附近稍稍凸出的球體。

    地球的極直徑是 12,640 公里，而它的赤道直徑是 12,683 公里。它的平均周長是 39,842.72 公里。

    因為地球自轉(zhuǎn)，它被太陽照亮的一側(cè)是是白天，而處在黑暗中的一側(cè)是夜晚。

    地球按照逆時針方向或者由西向東自轉(zhuǎn)。因此，我們看到太陽從東方升起。

    地球以每小時 1,680 公里或者每分鐘 28 公里的速度自轉(zhuǎn)。

    地球的軸線傾斜 23.5 度。因為這個傾斜，白天和夜晚的小時數(shù)并不全是 12.

    公轉(zhuǎn)是地球圍繞著太陽轉(zhuǎn)的旅程。地球所遵循的假想路徑是它的軌道。

    地球花 365又1/4 天完成一次公轉(zhuǎn)。這個一顆行星完成一次公轉(zhuǎn)所花的時間被稱為一年。

    地球以每小時 105,600 公里或者每分鐘 1,760 公里的速度公轉(zhuǎn)。

    地球的軌道是橢圓形的。在軌道上最接近太陽的點被稱為近日點，而最遠離太陽的點被稱為遠日點。地球離太陽的平均距離為 148,800,00 公里。

    因為地球軸線的傾斜而發(fā)生四季。在北半球，夏季具有較長的白天和較短的夜晚。在冬季則是晝短夜長。相反的情況發(fā)生在南半球。

    一個球體可作為地球的模型。球體的頂部是北方，它的底部是南方，它的左側(cè)是西方，而它的右側(cè)是東方。

    從北極到南極劃出的線被稱為經(jīng)線。從西向東劃出的線被稱為緯線。

    赤道以北或者以南以度數(shù)測量的距離被稱為緯度。經(jīng)度是本初子午線以東或者以西以度數(shù)測量的距離。

    本初子午線處于 0 度經(jīng)度，而國際日期變更線處于 180 度經(jīng)度。赤道處于 0 度緯度。

    為了在這個球體上找到準確的位置，要找出它的緯度和經(jīng)度。

    地圖是地球表面的平面表示或者圖形表示。地圖制作的技術(shù)被稱為地圖學(xué)。

    為了讀懂地圖，要注意指南針方向、圖例以及基準線。

    地球上的 24 個時區(qū)與在這個球體上按 15 度的間隔畫出的 24 根經(jīng)線相對應(yīng)。

    日歷顯示一年的 12 個月份。9月、4月、6月、11月有 30 天，而其它的幾個月除了2月份 28 天之外，都有 31 天，.