occur相关的词根或词缀是: cur curcurrcurscourcours

第三人称单数： occurs
过去式： occurred
过去分词： occurred
现在分词： occurring

Might such an internal adjustment even occur naturally ?

这样的内部调整会自然而然地发生吗？

That is because that pain will occur anyway .

这是因为痛苦无论如何都会出现。

The isotope does occur in nature but only extremely rarely .

钋的同位素在自然界中的确存在，但是相当罕见。

That will only occur if the us now gives the leadership we need .

只有美国现在承担起我们所需要的领导责任，这一切才可能实现。

These events are unlikely to occur simultaneously .

这两种情况不太可能同时发生。