1、occur

发生

If headaches only occur at night, lack of fresh air and oxygen is often the cause.

如果只是在晚上头疼，那常常是由于缺乏新鲜空气和氧气的缘故2hz9QVOz&C。

The crash occurred when the crew shut down the wrong engine.

机务人员关错了引擎，随即飞机坠毁PLI,JgixYY。

存在；出现；有

The cattle disease occurs more or less anywhere in Africa where the fly occurs.

在非洲凡是有这种蝇虫的地方，几乎都会出现这一牛病3HOZww62B8j[f)M%p。

These snails do not occur on low-lying coral islands or atolls.

在地势低平的珊瑚岛或环礁上没有这种螺mv5(+4yal^)1E]。

（想法或主意）被想到，被想起，浮现于脑海中

It did not occur to me to check my insurance policy.

我没有想到要核实我的保险单条款0Q-FW|;%f(16A%v。

It occurred to me that I could have the book sent to me.

我想到可以让人把书寄给我8~-|U,u%jgTkUK@%hWp。

2、carry out

实施；执行；实行

The Social Democrats could still carry out their threat to leave the government.

社会民主党人仍有可能将其退出政府的威胁付诸实施SnY*bY_MJnCQ5xNYv,JP。

Police say they believe the attacks were carried out by nationalists.

警方说,他们认为袭击是民族主义分子发动的j))#RT2u.-3。