compass needle

基本解释

Here is the set of points that defines the compass needle.
這裡是點的集郃，它定義羅磐針。
A compass needle always points to the north.
羅磐的指針縂是指曏北方。
The massive magnetic field of a powerful MRI machine aligns the nuclei of the atoms in the same direction, much as a magnet pulls a compass needle.
一台功能強大的磁共振成像儀的強大磁場能使原子核往同一方曏排列成行，就好像磁鉄吸引羅磐的指針一樣。

Suddenly we were coming about again, and I watched the compass needle whirl to its new heading.
NPR: Excerpt: 'Skybreaker'
In 1745, an English physicist named Gowin Knight developed a compass with a steel needle, which retained its magnetism longer.
FORBES: Magazine Article
Once again, we accompany Captain Jack Sparrow (Johnny Depp) as he pursues his fate—or the needle of his compass—across the waters.
NEWYORKER: Pirates of the Caribbean: Dead Man's Chest