英语语法分析

After people have learned that magnets attract things, centuries passed after they took note of the fact that magnets sometimes also repel things.

在人们了解到磁铁能吸引事物之后，几个世纪过去了，他们才注意到磁铁有时也会排斥事物。

Change the filters on your air-conditioning vents. These filters are dust and pollen "magnets".

更换空调通风口的过滤器。这些过滤器是灰尘和花粉的“吸铁石”。

Some magnets may have a mark to identify which surface is the northpole.

有些磁铁可能有标志以确定哪些表面是北极。