不定项选择题 
What is the discovery of the second experiment? ( )
A Asymmetric and non - asymmetric sleep patterns show the same reaction to the sounds.
B
The left hemisphere responds more to external stimuli due to FNE.
C
Asymmetric sleep pattern is more perceptive to external stimuli.
D
Unihemispheric slow wave sleep can help stay alert to potential threats.
