The waxy coating on the needles protects their leaves from the cold.

针叶上的蜡质涂层保护它们的叶子免受寒冷的侵袭。

But when he brought the magnet close to a wire carrying a current, the magnetic field from that current exerted a force on the needle, moving it to point in a different direction.

但是，当他将磁铁靠近载有电流的导线时，电流产生的磁场会对针施加一个力，使其指向不同的方向。