為什麼月亮繞著地球轉?

月亮為什麼繞著地球轉

引力平衡作用,地球和月亮是圍繞同一個引力中心轉動的，平衡點訂地球的接近地心的位置，地月系統其實也是一個雙星系統。只不過地球的引力遠大於月亮引力，看起來月亮就成地球的衛星了.

What is Copyright Protection? A brief memorandum regarding copyrights in general and as may be a ..

What is Copyright Protection? A brief memorandum regarding copyrights in ge What is Copyright Protection? A brief memorandum re撫arding copyrights in ge What is Copyright Protection? A brief memorandum regarding copyrights in ge What is Copyright Protection? A brief memorandum regarding copyrights in ge What is Copyright Protection? A brief memorandum regarding copyrights in ge