四级Cairo is known for its overcrowded roads, irregular driving practices and shaky old vehicles, but also for its air pollution.

开罗以其拥挤的道路、不规则的驾驶习惯和摇摇欲坠的旧车而闻名，但也因其空气污染而闻名。

2015年12月听力原文

四级She worked out that, if the left hemisphere was staying alert to keep guard in a strange environment, then it would react to the irregular beeps by stirring people from sleep and would ignore the regularly timed ones.

她计算出，如果左半球在陌生的环境中保持警觉以保持警惕，那么它会对不规则的嘟嘟声做出反应，将人们从睡眠中唤醒，并忽略定时的嘟嘟声。

2017年12月四级真题（第一套）阅读 Section C

四级We have John standing by the time clock, and he swears he saw nothing irregular.

我们有约翰站在时钟旁边，他发誓他没有看到任何不规则的东西。

2016年12月四级真题（第一套）听力 Section B

四级Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed of the same tone and irregular beeps of a different tone during the night.

佐佐木重新进行了这项实验，同时向睡眠中的参与者呈现了夜间定时的相同音调和不规则的不同音调的嘟嘟声。

2017年12月四级真题（第一套）阅读 Section C

四级Curious if the left hemispheres were indeed remaining awake to process information detected in the surrounding environment, Dr. Sasaki re-ran the experiment while presenting the sleeping participants with a mix of regularly timed beeps (蜂鸣声) of the same tone and irregular beeps of a different tone during the night.

由于好奇左半球是否真的保持清醒以处理周围环境中检测到的信息，佐佐木博士重新进行了实验，同时向睡眠的参与者发出了定时的嘟嘟声(蜂鸣声) 相同音调的不规则嘟嘟声和不同音调的不规律嘟嘟声。

2017年12月大学英语四级考试真题（第1套）