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。
Rattlesnakes occur in the warmer, drier parts of North America.
响尾蛇出现在北美温暖干燥的地区。
Such events occur only when the external conditions are favourable.
此类事件只有当外界条件有利时才会发生。
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。
If the climate gets drier, then the logical conclusion is that even more drought will occur.
如果气候变得更干燥，那么符合逻辑的结论就是甚至更多的旱灾将会发生。
Scientists warned that emergency cooling systems could fail and a reactor meltdown could occur.
科学家们警告说紧急冷却系统可能失灵，核反应堆的堆芯熔毁可能会发生。
Crater cracks occur when a crater is not filled.
当火山口没有被填满时，就会出现火山口裂缝。
The time when a solar eclipse will occur can be calculated.
日食发生的时间可以推算出来。
Earthquakes can and do occur at all depths to about 460 miles.
地震在460英里深度的地方都有可能发生，也确实会发生。
Why did the near extinction and migrations of wild animals occur?
为什么会发生野生动物濒临灭绝和迁徙的现象？
When these side effects occur, they are called adverse reactions.
当这些副作用发生时，它们被称为不良反应。
This causes an exception to occur in the RPG program being handled.
这将导致正被处理的RPG程序内部出现一个异常。
When these side effects occur, they are called "adverse reactions".
当这些副作用发生时，它们被称为“不良反应”。
They occur on a wide range of soil types and in extremes of climate.
它们广泛存在于各种土壤类型和极端气候中。
Waterlogged soils occur in areas that are flat or have poor drainage.
涝渍土壤发生在地势平坦或排水不畅的地区。
Assaults often occur on Friday and Saturday nights, near the bars downtown.
袭击通常发生在周五和周六的晚上，在市中心的酒吧附近。
Changes in the eccentricity of Earth's orbit occur in a cycle of about 96,000 years.
地球轨道偏心率的变化大约在96000年的一个周期内发生。
In 6% of cases, an inverse distribution may occur, with rash mostly on the extremities.
在6%的病例中，可能出现相反的分布，皮疹主要发生在四肢。
Thousands of deaths and other casualties are expected if a 9.0 earthquake were to occur.
如果发生9.0级地震，预计将有数千人死亡和其他伤亡。
In areas where the virus is widespread, most HAV infections occur during early childhood.
在病毒传播广泛的地区，大多数甲型肝炎感染发生在儿童早期。
Its numbers fall tenfold to thirty in a typical cycle, and a hundredfold change can occur.
在一个典型的循环中，其数量会以十倍到三十倍减少，甚至会出现一百倍的变化。
Commuter diatoms, for example, emerge only during those low tides that occur during the day.
例如，往返于通勤硅藻只在白天出现低潮时出现。
They think that a new subduction zone might occur at the western edge of the Atlantic Ocean.
他们认为，一个新的俯冲带可能会出现在大西洋的西部边缘。
Juan Louis, a junior geology major, decided to give an informative speech about how earthquakes occur.
地质专业大三学生胡安路易斯决定做一个有关地震如何发生的内容翔实的演讲。
It is at the boundaries between plates that most of Earth's volcanism and earthquake activities occur.
地球上大部分的火山活动和地震活动发生在板块之间的边界处。
While such repression may occur, people cannot remember ordinary events from the infant and toddler periods either.
这种压抑可能发生，但人们也同样不记得婴儿和学步期的普通事件。
Additional breathing changes occur during REM sleep that are even more dramatic than the changes that occur during NREM.
在快速眼动睡眠期发生的额外的呼吸变化，甚至比那些在非快速眼动期发生的变化还要显著。
The words 'heavy' and 'rain' co-occur frequently.
heavy和rain 两词频繁同现。
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