So it's trigonal because we have these three atoms that are bound to the central atom here, and if you picture it, it's actually shaped like a pyramid.

这里三角形是因为,我们有3个原子核中心原子成键，如果你画它，它就是金字塔形的。

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So you got like a surfboard-shaped board and put wheels on it, so they could ride it.

找一块冲浪板形状的板子，加上轮子，就可以滑了。

滑板的魅力 - SpeakingMax英语口语达人