occur /əˈkɜː/ star4 CET4 TEM4 (occurring,occurred,occurs)

• 1.  

  V-I（不及物动词） When something occurs, it happens. 发生

  例：

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

  如果头痛只发生在晚上，缺少新鲜空气和氧气常常是其原因。

• 2.  

  V-I（不及物动词） When something occurs in a particular place, it exists or is present there. (某事物在某地) 出现

  例：

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

  这些蜗牛不会出现在低洼的珊瑚岛上。

• 3.  

  V-I（不及物动词） If a thought or idea occurs to you, you suddenly think of it or realize it. (想法、主意在某人脑海中) 突然出现 [no passive, no cont]

  例：

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

  我没想到要核对我的保险单。