指南针为什么总是指向北方？

The earth is like a huge magnet. 地球本身，就是一块大磁铁。 A compass has a small needle inside. 指南针里，藏着一根小磁针。 The needle turns to point to the north. 小针转来转去，总想指着北边。 It feels the earth's quiet pull. 它能感觉到地球轻轻的拉力。 Wherever you go, it still points north. 你走到哪儿，它都指着北边。 Sailors used compasses for hundreds of years. 几百年来，水手全靠它认路。 A tiny needle can show you the way home. 一根小针，就能帮你找到回家的路。